This PDF file contains the front matter associated with SPIE Proceedings Volume 10313, including the Title Page, Copyright information, Table of Contents, and Conference Committee listing.

The nonlinear nonperturbative response of atoms in intense laser fields has been extensively studied both experimentally and theoretically in the past twenty years leading to new unexpected effects such as Above Threshold Ionization, ATI, high order frequency generation etc. and these are documented in recent book The similar studies of molecules is a new chapter in the pursuit of laser control and manipulation of molecules. The nonlinear nonperturbative response of molecules to intense (I<1015 W/cm2 ) and ultrashort (V10 fs) laser pulses [2] is expected to yield new effects due to the extra degrees of freedom nuclear motion as compared to atoms [3], such as creation of Laser Induced Molecular Potentials, LIMP' s, Charge Resonance Enhanced Ionization, CREI [4] and molecular High Order Harmonic Generation [5]. These nonlinear nonperturbative in effects were seen in experiments [6] and were predicted and confirmed by high-level numerical simulations of appropriate time-dependent Schrodinger equations [3-5,7], TDSE's, of molecules in laser fields. Our recent supercomputer simulations of H2+ molecule dynamics in intense laser fields, [7-9] based on TDSE, also allowed us to propose two new molecular imaging techniques: a) LCEI, Laser Coulomb Explosion Imaging [8] and b) LPEI, Laser Photoelectron Imaging [9]. The first is based on the analysis of the kinetic energy of molecular fragments after Coulomb Explosion, CE, whereas the latter imaging uses the shape of ATI electron peaks, produced by an intense laser pulse. We describe summarily in the present communication these two imaging methods which were developed using high level supercomputer simulations

Femtosecond laser technology based on pulse stretching-compressing technique has been demonstrating tremendous achievements [1], but it is still complicated and expensive. In this report we present a new generation of simple and robust high peak power diode-pumped Raman lasers. They are capable of producing laser pulses in picosecond range with pulse repetition rate (PRR) from f=10 Hz to f=7.5 kHz. Passat Ltd. has recently developed Raman lasers operating in three PRR formats: low PRR (1 - 25 Hz), medium PRR (100 Hz - 1 kHz), and high PRR (2.5 - 7.5 kHz). Table 1 shows parameters of Raman lasers supplied with harmonic generators for each of the PRR formats specified above.

Laser ultrasonic measurements are emerging as an efficient means for remote probing of metals. This technique offers the possibility to perform non-contact measurements in a hostile environment, at high temperature, and on any kind of structure. There are two regimes for generating ultrasound in a metal: thermo-elastic and ablative. The former, uses low-energy laser pulses to heat the surface of the sample. The transient expansion of the near surface region launches compression waves into the sample. These displacements are very small (-10 pm) in metals because of the low optical penetration depth, such that lock-in detection techniques must be used for these measurements. In the ablative regime, a higher energy density laser pulse causes partial ablation of the target surface and ionisation of the ablated material. The plasma thus created can reach very high pressures, which causes the plasma to accelerate away from the surface and launches a compressive elastic wave into the sample. The amplitude of these waves is much greater (-10 nm) than those generated in the thermo-elastic regime and they can easily be measured by single shot interferometric techniques. Theoretical simulations of ablation by ultra-short laser pulses [F.Vidal et al., PRL, 86, 2573 (2001)] explore the generation of high frequency ultrasound waves (- GHz) in a thin aluminum film. These simulations indicate that the ultrasonic pulse duration is proportional to the laser pulse duration down to 100 ps, and that below 100 ps, further reduction of the laser pulse duration has little effect on the ultrasound pulse duration.

In order to study ultrashort laser-produced plasmas, we developped at INRS a subpicosecond x-ray streak camera, called the PX1. The PX1 has been completely characterized.' Using an extraction field of 250 kV/cm, a record 350 fs temporal resolution has been measured with x-ray pulses in the KeV range. Also, we obtained a 40 tim spatial resolution along the 15 mm slit of the photocathode in single-shot. The PX1 has also been used in accumulation mode and a temporal resolution of 800 fs has been obtained with unlimited dynamic range. Recently, in an effort to improve upon these results, a new x-ray streak camera has been developped and tested. This camera, called the FX, uses the new generation of bilamellar tube technology. This includes a better control of the paraxial trajectories, a larger quadripolar lense to increase the usable width of the photocathode and a new design of the electronic lenses to permit the use of higher voltages.

Many oxides undergo insulator to metal phase transition. For example, eight vanadium oxides undergo such a transition. The transition of vanadium dioxides (V02) was first reported in 19591 and has been characterized by several different means. Recently, the developments of femtosecond laser technologies have made possible time resolved studies of this phase transition. The purpose of this study is to investigate the correlations between electronic and atomic dynamics during the phase transition as a function of the laser conditions and the physical properties of thin films of V02. These experiments were realized in two steps: in the first step, we characterized the visible response of the samples. The structural dynamic of the phase transition using time resolved x-ray diffraction has been studied in a second step.

Femtosecond laser have been useful in the optical domain to understand the dynamics of ultrafast system. However, theses techniques only yield indirect information on the structural change. The extension of the pump-probe technique to the x-ray can provide at the same time, temporal and structural information, giving a molecular movie of a chemical reaction.

We describe a hybrid semiconductor saturable absorber mirror (SESAM) structure that has been developed as a passive mode-locking element for use with Cr:YAG, and other low gain laser systems. In addition to describing the device and its fabrication we report the results of initial mode-locking experiments carried out with a Cr:YAG laser. Mode-locked pulses as short as 500 fs have been generated.

We have developed a high intensity, dual-wavelength laser system to carry out vibrational excitations of molecules via mid-infrared radiation [1] or Raman Chirped Adiabatic rapid Passage (RCAP) [2,3]. We have previously reported amplifying two outputs from a dual-wavelength, mode-locked Ti:sapphire laser to a total energy of 1.5 mJ, in a single regenerative amplifier [4]. Also we have reported the generation of 1.5 ILI pulses at 10 [an, from mixing the output of the two colour amplifier [5] . In this report, we describe a dual-wavelength, multi-pass amplifier, that increases the energy of the two pulses to a combined level of 15 mJ. The two pulses can be used directly in an RCAP experiment or be difference frequency mixed to generate high intensity mid-infrared radiation, for the chirped mid-infrared experiment. We have now increased the energy to 7.4[0, by using 4.7 mJ of energy from the multi-pass amplifier.

Introduction Mass spectrometers are used to determine the masses of atoms, molecules, and clusters in a wide range of applications. Presently, there is a drive towards the miniaturization of such devices for use in spacecraft life support, pollution monitoring, and explosives/narcotics detection applications. For a given mass resolution, the ion flight distance (and hence the size) of a time-of-flight (TOF) mass spectrometer is related to the length of the ionization region along the flight axis. Since femtosecond pulses can ionize atoms and molecules within a very small focal volume with near unit efficiency, they are compatible with miniature mass spectrometers. We have demonstrated a general technique for compact TOF mass spectrometry using two spatially separated laser foci. The first femtosecond laser pulse ionizes a gaseous sample and the second pulse probes for the presence of a specific mass in the analyte. Our approach enables TOF mass analysis to be performed on a sub-millimetre length scale. Furthermore, the second pulse can be intense enough to explode the molecules it probes. Using such laser- induced Coulomb explosion for molecular detection yields a significant improvement in detection efficiency for large molecules. Taken together, these developments can reduce the size and complexity of miniature TOF mass spectrometers and allow the fabrication of integrated mass analyzers with relaxed voltage, vacuum, detector, and timing electronics requirements.

Semiconductor diode lasers can provide compact sources of ultrashort light pulses [1-2]. Our research efforts are aimed at the development of a widely tunable, diode laser source for the generation of picosecond, and ultimately sub-picosecond, pulses. The InGaAsP/InGaAs active region of the diode is composed of two quantum wells [3-4] grown lattice matched to GaAs. Work is done using both symmetric and asymmetric structures. All laser structures are grown using the McMaster molecular beam epitaxy facility. Mode-locking is achieved with the diodes in an external cavity configuration. The two different quantum wells allow a 64 nm tuning range centered at 985 nm. Typical pulse durations measured directly from the diode are found to be between 3 and 15 ps. The mode-locked output from the external cavity laser is then coupled into a semiconductor optical amplifier to increase the pulse power. The active regions of the amplifiers are based on the same InGaAsP/InGaAs material as for the oscillators. Our initial amplification work focuses on narrow stripe geometries. This provides large bandwidth, single pass traveling wave amplification. The effect of amplification on pulse shape is measured using a cross-correlation technique. In this technique, the ps pulses are frequency mixed through a nonlinear crystal with 80 fs, 795 nm pulses from a mode-locked Ti: Sapphire laser.

The enhanced ionisation thresholds for the triatomic OCS molecules have been determined using a classical model. By using these thresholds to determine the dissociative motion of an OCS molecule in a 55fs laser pulse of intensity 2x10'5 W/cm2, the accuracy a Coulomb imaging experiment has been quantified.

Femtosecond lasers have proven to be very useful tools for the microstructuring of solid targets [1, 2, 3]. The ablation of metals using conventional lasers is accompanied by formation of substantial heat-affected zones. Extremely fast energy deposition and rapid ablation with small heat-affected zones make it possible to achieve controllable ablation and production of high-quality structures in metallic materials. A significant improvement in this field has thus become possible because of ultrashort pulse lasers. With ultrashort-pulse laser systems, measurements of laser-induced damage and ablation thresholds on metals have been performed for both a very broad range of pulse durations and wavelength regions. Comprehensive ablation experiments of metals such as Cu, Al, Fe, Au, and Ag by using solid state and excimer femtosecond have been reported [1-5]. In this study, we investigated the effects of femtosecond laser irradiation on metals via study of scanning electron microscopy (SEM), atomic force microscopy (AFM) and transmission electron microscopy (TEM).

The recent discovery of superconductivity at 39 K in magnesium diboride, MgB2, [1] stimulated extensive research of this material's physical properties and future applications in superconducting electronics and optoelectronics. We report here our studies on optical photoresponse of superconducting MgB2 thin films using the femtosecond pump-probe spectroscopy [2,3]. In pump-probe experiments, the output of an ultrafast laser is divided into two beams. One beam is used to excite the sample. Since the pulse duration is only -100 fs, it acts as a delta-function-type excitation. The second beam probes the changes induced by the excitation, usually either as the relative change of reflectivity or transmissivity by as a function of the relative time delay to the pump beam. The probe beam is much weaker than the pump beam to ensure that the changes in the material are induced only by the pump beam. With femtosecond spectroscopy, we are able to study the dynamics of electrons and the electron-phonon interaction with subpicosecond resolution. In our experiments, a commercial Ti:Sapphire femtosecond laser with 76 MHz repetition rate is used to generate 100-fs-wide, 800-nm-wavelength optical pulses.

NbN superconducting single-photon detectors (SSPDs) are very promising devices for their picosecond response time, high intrinsic quantum efficiency, and high signal-to-noise ratio within the radiation wavelength from ultraviolet to near infrared (0.4 gm to 3 gm) [1-3]. The single photon counting property of NbN SSPDs have been investigated thoroughly and a model of hotspot formation has been introduced to explain the physics of the photon- counting mechanism [4-6]. At high incident flux density (many-photon pulses), there are, of course, a large number of hotspots simultaneously formed in the superconducting stripe. If these hotspots overlap with each other across the width w of the stripe, a resistive barrier is formed instantly and a voltage signal can be generated. We assume here that the stripe thickness d is less than the electron diffusion length, so the hotspot region can be considered uniform. On the other hand, when the photon flux is so low that on average only one hotspot is formed across w at a given time, the formation of the resistive barrier will be realized only when the supercurrent at sidewalks surpasses the critical current (jr) of the superconducting stripe [1]. In the latter situation, the formation of the resistive barrier is associated with the phase-slip center (PSC) development. The effect of PSCs on the suppression of superconductivity in nanowires has been discussed very recently [8, 9] and is the subject of great interest.

Photoconductive devices based on various semiconductor materials such as ion-implanted InP,1' 2' ion-implanted silicon-on-sapphire,3 amorphous silicon and low-temperature-grown GaAs (LT-GaAs),`-7 as well as metal- semiconductor-metal diodess have been under investigation to generate picosecond and subpiconsecond electrical pulses for the last two decades. Those photoconductive switches, however, suffer from a difficulty to integrate them with optoelectronic circuits due to their nonstandard active materials. The hybrid integration unavoidably reduces their intrinsic multigigahertz bandwidth. We present here a new method of making a freestanding LT-GaAs photoconductive switch, which can be placed at virtually any place of the circuit containing a coplanar strip (CPS) transmission line. We also demonstrate that the freestanding LT-GaAs photoswitch exhibits a subpicosecond photoresponse time.

Superconducting detectors become the most prominent technology for radiation sensors with ultimate performance. Typically, they are nanostructures formed from an ultra-thin superconducting film incorporated into an external antenna for efficient radiation coupling. The operation of so-called hot-electron bolometers and photodetectors (HEBs and HEPs) is based on nonequilibrium heating of the electron subsystem by the absorbed radiation and results in the film resistance and a corresponding, easily measurable voltage response when device is current biased [1-2]. A relatively simple, single-layer manufacturing technology made these devices very popular for needs of radioastronomy and remote sensing.

Josephson-junction-based low temperature rapid single flux quantum (RSFQ) superconducting electronics is already a mature technology, which is expected to perform at speeds exceeding 100 GHz [1]. However, the RSFQ technology still lacks a fast enough output interface between its operating circuit temperature T = 4.2 K and the room temperature electronic environment. RSFQ circuits work at liquid helium temperatures and the direct interconnection of these circuits and room temperature circuits using, e.g., copper transmission lines would consume too much of the cooling power [2]. To solve this problem a magneto-optical (MO) output interface has been proposed [3], in which the output current pulse from the RSFQ circuit is converted into an optical pulse and delivered to room temperature readout circuitry via an optical fiber.

The Canadian community propose to establish a Canadian based International Research Facility that will explore a completely new approach to dynamic investigation of matter. The basic goal is to provide the research community with tools to image changing molecular structures. The approach will be based on recent advances in ultrafast technology to provide a new generation light source for molecular imaging. The facility, called the Advanced Laser Light Source (ALLS), will enable the combination of any or all of the most advanced laser technologies for exploiting light-matter interactions. This facility will bring together some of the most outstanding researchers in biology, chemistry, and physics around Canada and the world to work collectively towards this vision.

The frequency downshifting of fundamental laser output via stimulated Raman scattering has been previously demonstrated and studied mainly with flash-lamp pumped Q - switched Nd:YAG lasers [1,2]. With the advent of diode - pumped lasers it was an issue of time when the technique of Raman conversion would be applied to such lasers. Recently there appeared a number of publications in which Raman lasing is reported in diode - pumped lasers (see, for example [2-4]).

The Neptec Design Group has developed the Laser Camera System (LCS), a new 3D laser scanner for space applications, based on an auto-synchronized principle from the National Research Council of Canada (NRC). The LCS was tested in August 2001 during mission STS-105 of the space shuttle Discovery to the International Space Station'.

The Neptec Design Group has developed a Laser Camera System (LCS) that can operate as a 3D imaging scanner. The LCS uses an auto-synchronized triangulation scheme to measure range information while two orthogonal scanning mirrors sweep through the field-of-view. The LCS simultaneously records intensity of the reflected laser beam and range information. The intensity data can be used to produce 2D grayscale images as well as to map the intensities onto 3D surface models. The nature of triangulation geometry dictates that such measurements are best for close objects, with range error increasing with the square of object rangel. The LCS was flown in the payload bay of the shuttle Discovery during mission STS-105. Four scans were taken of the same scene while the shuttle was docked to the International Space Station (ISS)2. Partially visible ISS elements included the SSRMS (Canadarm2), Multi-Purpose Logistics Module (MPLM), Destiny Lab Module, Node 1 (Unity), Joint Airlock Module (Quest), and several solar arrays.

The Neptec Design Group has developed the Laser Camera System (LCS), a new 3D laser scanner for space applications, based on an autosynchronized principle from the National Research Council of Canada (NRC). The LCS operates both in imaging and target centroid acquisition modes. In imaging mode, the LCS raster scans objects and can produce 2D and 3D maps of their surface features. In centroid acquisition mode, the LCS determines the position of discrete target points on an object. The LCS was tested in August 2001 during mission STS-105 of the space shuttle Discovery to the International Space Stations. From a fixed location in the shuttle payload bay, the LCS 1500 nm eye-safe infrared laser was pre-programmed to draw Lissajous patterns on Inconel (black dots on a white background) and retro-reflective disc targets affixed on the Multi-Purpose Logistics Module (MPLM). The LCS acquired centroid data for two and a half hours during the MPLM demating operation to demonstrate its ability to track both types of targets when they are stationary and moving.

Introduction The fully integrated Advanced Camera for Surveys (ACS) (Ford et al. 1998, SPIE Vol. 3356, 234), suc- cessfully installed in the Hubble Space Telescope (HST) in early March 2002, underwent a series of ground calibration tests at Ball Aerospace and Technologies Corporation (BATC) and at the Goddard Space Flight Center (GSFC) to verify its performance and flight readiness (Hartig et al. 1998, SPIE Vol. 3356, 321). The flight build detectors were installed in late 2000 and the majority of the flight quality data were acquired in the following year. The activities revolved around several major campaigns designed to characterize the flight build detectors and the optical and ultraviolet channels of the instrument and to verify the contract-end-item specifications. In the following, we briefly describe the different ground-based activities.

Over the past five years the feasibility of spaceborne differential absorption lidar (DIAL) systems for the purposes of trace gas monitoring in the atmosphere has been studied [1,2,3]. The feasibility of such instruments is supported by the results of studies such as ORACLE (Ozone Research with Advanced Cooperative Lidar Experiment: a joint study of NASA/LaRC and the Canadian Space Agency) and WALES (Water vApor Lidar Experiment in Space: a study by the European Space Agency). One crucial aspect determining spaceborne DIAL performance is the collecting telescope's aperture size. In this respect, the interests of the atmospheric remote sensing and the astronomy communities overlap, in that spaceborne telescope aperture size is a key performance driver for both applications. While the stringent optical performance requirements characteristic of astronomical instruments -and the success seen in reaching some of these goals for the Next Generation Space Telescope (NGST)- are encouraging for the realization of more modest spaceborne lidar telescope optical performance requirements, spaceborne DIAL telescope development nevertheless provides its own challenges.

SWIFT Objectives The primary objective of SWIFT Explorer is to provide high resolution global measurements of horizontal winds in the stratosphere for both day and night. Furthermore, SWIFT will measure the stratospheric ozone concentration co-located with the wind. The specific scientific objectives are tropical wind climatologies, transport studies and data assimilation.

The National Research Council of Canada, Herzberg Institute of Astrophysics has been developing a reconfigurable slitmask intended for the NGST near IR spectrograph. The Mechanically Actuated Reconfigurable Slitmask (MARS) creates 50 slits in the telescope focal plane. The slit location and width are adjustable, but the height is fixed. Reconfiguration of the mask components is achieved using a combination of electromagnetic and piezoelectric actuators. This actuation scheme has undergone structural, electrical, thermal and magnetic analysis. Several prototype components have also been built and tested. This analysis and testing indicates that the MARS device represents a viable concept for creating slits within the NGST near IR spectrograph.

The CALTRAC® star tracker is a space-borne attitude sensor, that uses a wide-angle all-reflective telescope with a highly curved image surface and a small f-number. There are a number of critical optical metrology activities that are involved in building the star tracker. These include, among others, aligning the optics and CCD detector subassemblies to form an optics head by using a five-star simulator, measuring angles between internal optical axes and external references for space-craft integration, positioning the vertex of the optics to the rotation axis of a 2D rotary table for subsequent optical calibrations, determining the lateral location of an internal CCD baffle, and verifying the precision of the 2D rotary table to arc- second accuracy. Optical measurements involved in these activities must be performed accurately, so as to ensure the overall performance of the integrated star tracker system. This paper is intended to introduce the methods of optical measurement that were developed for these purposes. Accuracy achieved with these methods has proven sufficient in supporting the development and production of the star trackers.

The Next Generation Space Telescope project in its early definition phases has given birth to many innovations in instrumentation for astronomy by providing funding for industries in an area often considered less lucrative and hence of lower interest. New alliances were formed with universities and institutions and the knowledge exchange lead to very interesting new concepts. The Imaging version of the Fourier Transform Spectrometer (IFTS), a derivative of the classical Michelson interferometer that has been used successfully in spectroscopy for decades, was introduced in military applications in the mid 80's with small FPA (- 2 X 4).

Optical design is both an art and a science. There is any computer program that will create lens design without guidance from an optical designer. Understanding the engineering trade-offs will help you choose the right lens design for your application. With the increasing complexity and precision of space-based and astronomical optical system, the effects of the environment upon optical system reliability are becoming more important. Some phenomena pose potential threats to the success of optical instruments. We present some of them.

Liquid mirrors are an established technology; they have proven to be a viable low cost alternative to conventional glass optics in several applications. We are working to expand the capabilities of liquid optics by developing a material that can be deformed rapidly in a precise manner as is the case for conventional solid optics while maintaining the low cost and relative ease of construction of current liquid mirror devices. In this paper we discuss the application of a new ferrofluid based technology to the problem of deformable mirrors in adaptive optics.

This work forms part of The Hyperspectral Mission (THM) program, funded by the Canadian Space Agency. The designs correspond to three mission profiles with the parameters listed in Table 1. Two of the potential missions are designed for a flight on the EXPRESS external pallet of the International Space Station (ISS). All designs make use of push-broom imaging, whereby a slit is scanned across the scene by the orbitiil motion of the platform. In the case of the Enhanced ISS and Small Satellite designs there is an option to use ground motion compensation to reduce the ground sampling distance. There is also a common requirement for all the designs for a 0.4ftm to 2.5pm spectral waveband but there are varying requirements for instrument field, spatial and spectral resolution.

The Instrument Group at the Dominion Astrophysical Observatory (DAO) is a group of engineers and specialists whose main work is the design, production, and testing of instrumentation for large astronomical telescopes. Areas of expertise include electronic, mechanical, optical, and software engineering. Some notable instruments that have been completed are the adaptive optics system for the Canada-France-Hawaii 3.6-metre telescope (CFHT) and a multi-object spectrograph for the Gemini North 8-metre telescope, both on Mauna Kea in Hawaii. Projects now being designed or built include a second multi-object spectrograph for Gemini South in Chile, an adaptive optics system for Gemini North, components for a wide-field camera for CFHT, and preliminary design of components for an adaptive optics system for Gemini South. Because of the operating environment of the instruments and the precise tolerances required for optical alignment, these instruments produce unique design problems that need to be solved to meet instrument specifications. The following summary is a description of the methods developed for the mounting of lenses and mirrors.

The Herzberg Institute of Astrophysics (HIA), AMEC Dynamic Structures Ltd. and several other Canadian university groups are currently in the initial phases of designing a new 20-25 metre class, ground-based, optical telescope called the Large Optical Telescope (LOT). At more than six times the collecting area of current state-of-the-art telescopes, the LOT will enable Canadian astronomers to continue carrying out forefront astronomical research. However, the LOT presents difficult design challenges not encountered with previous observatories. The successful design, construction and operation of the LOT will not only require detailed studies of all major telescope subsystems but will also require a fully integrated model of the entire observatory.

A nanosatellite controUcommunications concept is described using a 'state machine' control paradigm and optical communications to dramatically reduce the mass and power consumption for payloads that can tolerate a low, intermittent data rate.

The paper reports on recent progress in electro-optical and photonics developments at the Canadian Space Agency / Space Technologies / Optical Instrumentation Group. Technology R&D projects in active sensing, lasers and Optical Inter-Satellite Links (OISL) are underway both in-house and in contracting out to Canadian industry. In-house projects are concerned with: - Research and development of a novel all-optical tracking technique for OISL using non-linear optical concepts; these include development of a high-speed communication interface and search for efficient non-linear / optical / laser / light-weight materials to work in the space environment. - Development of space vision systems - an eye-safe laser scanner for 3D-tracking and imaging, and a stereo vision system for object recognition and pose tracking linked to a robotic test-bed (in cooperation with CSA Spacecraft Engineering / Robotics Group); CSA has supported the development of a laser vision system that was demonstrated on a recent Shuttle flight.

The infrared astronomy group at the Universite de Montreal has been involved in building instruments for the past 20 years, to support its own research projects or under contract with the Canada-France-Hawaii Telescope Corporation and the National Research Council. A camera for the detection of faint objects around nearby stars, a multiobject spectrograph for the 0.8pm to 2.5pm spectral range, and a wide field camera, funded by the Natural Sciences and Engineering Research Council and the Canadian Foundation for Innovation, have been designed recently and are described below. The triple-imager Trident

Research in organic solid and polymer-based optoelectronic devices is driven by the physical flexibility, low cost, processability, and almost infinite spectrum of functional possibilities offered by organic materials. Many active components currently used in fiber-optic communication system reply on the use of inorganic semiconductors and mechanical means, which makes each of the components bulky, rigid and independent. Photonic on-chip integration is extremely difficult with current components and materials. Thus, there is a need for a new and emerging class of organic materials for use in a range of important optoelectronic components, which enables improvement and revolution in device performance, device miniaturization and on-chip integration.

Recently we have started a project on a new type of azobenzene polymers, namely azobenzene elastomers (AEs). Our purpose is to investigate the coupling effects between mechanical stretching and photoisomerization of azobenzene and to explore the potential of using azobenzene elastomers for mechanically tunable optic or photonic devices. The polymer shown below is such a thermoplastic elastomer that is obtained by grafting an azobenzene side-chain liquid crystalline polymer (SCLCP) onto a styrene-butadiene-styrene triblock copolymer (SBS).1 The concentration of the azobenzene-SCLCP ranges from 10 to 20 wt %.

We have synthesized azobenzene-containing chiral gelators for liquid crystals (LCs), two of which, AG1 and AG2, are shown below. When dissolved in a LC host, driven by intermolecular hydrogen bonding, the gelator molecules are able to gel the LC through the formation of fibrous aggregates that lead to a non- covalent network. A variety of interesting phenomena were observed for this new type of functional materials.

Recently, there has been much attention focused on photonic crystals and photonic bandgap materials [1]. The fabrication of these materials requires the formation of a periodic variation in the refractive index on a submicrometer length scale. It is anticipated that these structures will provide the building blocks required for future photonic devices and photonic integrated circuits. Applications are envisaged for structures with both 2- and 3-dimensional periodicity. In this communication we report results from a novel variant of ion beam lithography. The approach involves ion implantation through a mask of silica microspheres, followed by selective chemical etching.

We have studied the dynamics of photocarriers in doped InAs/GaAs self-assembled quantum dots using time- resolved photoluminescence measurements. The influence of the excitation conditions (excitation power, wavelength) and the effect of the doping level have been investigated. The rise time of the quantum dot emission signal is correlated with the number of carriers inside the dots whether they are introduced by doping or by photoexcitation. In both cases, the photoluminescence rise time diminishes with the number of carriers. A four-level model taking into account different interlevel relaxation and capture mechanisms has been used for the simulations of the photoluminescence transients. Discussion on the physical hypothesis behind this model is given.

The nonlinear optical properties of mixed (merocyanine dye + fatty acid) Langmuir-Blodgett multilayers were investigated using second-harmonic generation for possible device application. The influences of the dye concentration and the number of monolayers on the intensity and the spectral shape of the second harmonic signal are reported.

Organic materials suitable for application in electronics (e.g., thin film transistors and) and optoelectronics (e.g., light emitting diodes) have received increasing attention during the past years. Such new compounds are not designed to replace the existing technology where speed and stability under extreme conditions are vital. These compounds could be potentially used for applications that require short-term use and large- scale manufacture. Of great interest as novel materials are substituted pnetacenediquinones for optoelectronics applications, substituted pentacenes for thin film transistors and indenofluorene derivatives for applications in light-emitting diodes. Pentacenediquinones are compounds that contain five aromatic rings in a row and two quinoid moieties in their structure. Pentacenediquinones can be easily reduced electrochemically to the corresponding semiquinone (radical anion). The semiquinone displays absorbance in the near-infrared (NIR) region, between 1300 and 1500 nm.1'2 By introduction of various substituents on the two "outside" aromatic rings (figure 1), the semiquinones of substituted pentacenediquinones offer a possibility to fine tune the MR activity in the three telecom windows: 1550, 1310 and 880 nm.

A series of linear and hyperbranched poly(ether imides) containing diacetylene moieties are synthesized. Control of refractive index of the polymers can be achieved by varying the ratio imide/ether content. For the linear polymers the in-plane refractive index (nm) at 1550nm can be tuned between 1.5454 and 1.6313 by changing the ratio of two monomers. The maximum value is reached at 100 mol% of the imide monomer. The arm value can also be controlled between 1.5329 and 1.6283 by varying the monomer ratio. Decrease of birefringence was obtained by increasing the ether monomer content, from 1.25x10-2 to 3x10-3. The refractive indices of the hyperbranched polymers vary from 1.5646 to 1.6263 for nm and from 1.5584 to 1.6277 for nm. The chain branching causes a significant reduction of the birefringence to as low as 2x104 for polyTPPE and 6.2x10-3 for the hyperbranched poly(ether imides). UV curing of the thin polymeric films produces small changes in both nm and aim, lowering their value with an average of 5.5x10-3. Thermal curing produces coloration of the films, with an increase in refractive indices, both nm and arm.

With the increasing growth of semiconductor and photonics technology, the optical materials have attracted considerable attention since they can meet the demanding performance requirements for the telecommunication, data communication and information storage systems.1'2 One of the most interesting and fast-developing classes of optical materials is optical polymers, which show promising over silica and semiconductors as a platform technology for photonics integration in that optical polymers are able to provide increased functionality, rapid fabrication, much efficient power and furthermore they have the potential to facilitate next-generation hybrid active/passive devices.3'4 To achieve high level of photonics integration, planar waveguide technology is considered to represent one of the more significant technologies of the next decade that paves the path with innovative polymers, hybrid materials and low- cost integrated optical components, as well as brings about substantial advantages in some issues such as labor cost, component density and optical loss.5'6'7 A new class of curable optical polymers containing benzocyclobutenone (ca. BCBO polymers) has been developed as waveguide materials for photonic integration.8 BCBO (1) is a latent reactive ketene and readily undergoes thermal and photochemical reactions in quantitative yield with a variety of functional molecules such as an alcohol (Scheme 1).

Recent advances in flat-panel display technology have ignited the search for new powdered phosphors with nanometer dimensions. Currently, phosphors in the micrometer size range find applications in a wide variety of information display devices such as cathode-ray tubes (CRTs), field emission displays (FEDs), vacuum fluorescent displays (VFDs) and electroluminescent (EL) devices [1]. Micrometer sized Y203:Eu3+ phosphors have been used since the 1970's as the red component in television projection tubes and fluorescent lighting devices [2]. It is anticipated that the advent of nano- sized phosphors will lead not only to improved resolution but also to an increase in luminescent efficiency. A class of materials that has shown considerable promise in delivering these qualities are lanthanide doped nanocrystalline materials.

Oxide based glasses have proved to be interesting hosts due in part to their usefulness in the field of photonics. The addition of the tripositive erbium ion to the glass structure in the form of an impurity allows for the use of the glass host as a material for high power lasers and optical amplifiers. Erbium doped oxide glasses show a relatively broad emission band at approximately 1500 nm ascribed to the 4113/2 --< 4115/2 transition. This broadening of the emission band is due to the high degree of disorder inherent in all vitreous materials. Unlike in crystals where the environment of each ion is identical, individual dopant ions in a glass matrix will reside in different sites and thus, the spectra will consist of overlapping contributions from each distinct site. Furthermore, the luminescence lifetime of the 4113/2 state is long (milliseconds) and as such, these glasses are suitable for use as optical amplification devices [1]. For some applications, upconversion can prove to be deleterious and thus, any investigation into the optical properties of Er3+ glasses is not complete without studying its upconversion properties. Upconversion is a phenomenon whereby low energy photons, usually infrared, are converted into photons of higher energy. In this paper, we will present a detailed investigation of the optical properties of an erbium doped sodium phosphoniobate glass.

In modern WDM/DWDM based optical networks, wavelength division is very important. Bragg gratings are used in many devices to reflect, and thus isolate, specific wavelengths of light. Chalcogenide glasses can be used to create such gratings due to photorefractive effects that take place when illuminated with near bandgap light. We have created holographic Bragg gratings in As2Se3 films by using a HeNe laser to illuminate the glass in a periodic interference pattern. Refractive index changes of 0.009 have been measured.

In this paper, we report on the fabrication of Erbium doped waveguide amplifiers (EDWA's) using electron cyclotron resonance plasma enhanced chemical vapour deposition (ECR-PECVD). The salient process parameters are presented, as are the determination of the Er content through Rutherford Backscattering (RBS), and measurements of the film composition using elastic recoil detection (ERD), nuclear reaction analysis (NRA) and secondary ion mass spectroscopy (SIMS).

Electroluminescence in conjugated polymers was first discovered in poly(p-phenylenevinylene) (PPV)1. Since then research efforts on polymer-based light emitting devices have increased dramatically, primarily due to their potential application in full color flat panel displays and the low fabrication costs associated with this technology. Poly(phenylenevinylene) (PPV) and its derivatives have been widely used as emissive materials in polymer light emitting diodes (PLEDs). Conjugated polymers derive their semiconducting properties from delocalized It- electrons along the polymer chain. Therefore it is possible to modify the semiconducting properties of the polymer by adding different functional groups to the polymer structure thereby altering the extent of delocalization of the rc-electrons. The knowledge of how different functional groups in the PPV structure affect its physical properties is very important for understanding the structure-property relationship in this material. However, a broad molecular weight distribution and the presence of blocks with different conjugation lengths in the polymeric material often complicate the issue. In this sense, oligo(phenylenevinylene) (OPV) type of material is ideal to use as a model system to study the structure-property relationship. Due to controllable and well-defined chemical structures, it is much easier to follow and correlate the physical properties of the OPVs with the molecular structures. In addition, many oligomeric materials can be thermally sublimed under high vacuum, allowing for the preparation of multilayer organic light emitting diode (OLED) structures and devices in an ultra-clean and well-controlled environment thus overcoming the uncertainties involved in wet processes.

This paper describes a virtual private optical network architecture (Optical VPN - OVPN) based on virtual router (VR). It improves over architectures suggested for virtual private networks by using virtual routers with optical networks. The new things in this architecture are necessary changes to adapt to devices and protocols used in optical networks. This paper also presents information models for the OVPN: at the architecture level and at the service level. These are extensions to the DEN (directory enable network) and CIM (Common Information Model) for OVPNs using VRs. The goal is to propose a common management model using policies.

Telecommunication transmission systems continue to evolve towards higher data rates, increased wavelength numbers and density, longer transmission distances and more intelligence. Further development of dense wavelength division multiplexing (DWDM) and all-optical networking (AON) will require ever-tighter monitoring to assure an agreed quality of service (QoS), characterized by network availability and bit-error rate (BER). However, it becomes complex with traditional methods when applied in next generation networks. For the purpose of obtaining information quickly and accurately in future transmission systems, new monitoring schemes need to be developed and deployed. The paper provides a view of next generation monitoring requirements, business drivers as well as performance monitoring techniques, potentially applicable as next generation performance surveillance methods.

Normalized laser rate equations suitable for large signal analyses are discussed. A large signal laser model suitable for system level simulations is presented. Predicted laser modulation response characteristics are given for Fabry-Perot lasers and compared to measured results. The dependence of the laser modulation response on the laser relaxation-oscillation peak frequency and laser biasing is predicted and compared to measured values. It is demonstrated that the small-signal carrier modulation bandwidth is limited mainly by the intensity dependence of the modulation frequency and the laser's damping rate of oscillation. Simulated and measured results demonstrate that the relaxation-oscillation peak frequency is a reasonable estimate for the modulation bandwidth, and the variation of the modulation response with the output power is nearly flat at fixed modulation frequencies.

The dramatic growth of the Internet and the optical core network that supports it has recently slowed down in spite of a growing appetite for bandwidth-hungry services and applications, particularly those with video content. One of the major reasons for the pause is the lack of affordable broadband access transport facilities extending optical rate connectivity over the last mile.

The transmission of information as optical signals encoded on light waves traveling through optical fibers and optical networks is increasingly moving to shorter and shorter distance scales. In the near future, optical networking is poised to supersede conventional transmission over electric wires and electronic networks for computer-to-computer communications, chip-to-chip communications, and even on-chip communications. The ever-increasing demand for faster and more reliable devices to process the optical signals offers new opportunities in developing all-optical signal processing systems (systems in which one optical signal controls another, thereby adding "intelligence" to the optical networks). All-optical switches, two-state and many-state all-optical memories, all-optical limiters, all-optical discriminators and all-optical transistors are only a few of the many devices proposed during the last two decades. The "all-optical" label is commonly used to distinguish the devices that do not involve dissipative electronic transport and require essentially no electrical communication of information. The all-optical transistor action was first observed in the context of optical bistability [1] and consists in a strong differential gain regime, in which, for small variations in the input intensity, the output intensity has a very strong variation. This analog operation is for all-optical input what transistor action is for electrical inputs.

Directly modulated lasers at 1310 nm are useful as low cost short haul high speed transmitters. High speed requires large differential gain and high damping. Low cost dictates that the device can operate without a thermoelectric cooler (TEC) to temperatures of 85 C, preferably without introducing exotic designs or material features. A multiple quantum well (MQW) ridge waveguide (RWG) gain coupled (GC) distributed feedback (DFB) InGaAsP laser grown by metal-organic chemical vapor deposition (MOCVD) satisfies the above requirements.