In this paper, we propose a novel digital silicon-on- insulator (SOI) optical waveguide switch. Adding electrodes on a symmetric vertically coupling SOI switch, the device we can change light direction and coupling coefficient based on the plasma dispersion effect. The novel device is operated at wavelength 1550nm. Beam propagation method simulations show good output mode pattern.
The demands of exponentially growing Internet traffic, coupled with the advent of Dense Wavelength Division Multiplexing (DWDM) fiber optic systems to meet those demands, have triggered a revolution in the telecommunications industry. This dramatic change has been built upon, and has driven, improvements in fiber optic component technology. The next generation of systems for the all optical network will require higher performance components coupled with dramatically lower costs. One approach to achieve significantly lower costs per function is to employ Planar Lightwave Circuits (PLC) to integrate multiple optical functions in a single package. PLCs are optical circuits laid out on a silicon wafer, and are made using tools and techniques developed to extremely high levels by the semi-conductor industry. In this way multiple components can be fabricated and interconnected at once, significantly reducing both the manufacturing and the packaging/assembly costs. Currently, the predominant commercial application of PLC technology is arrayed-waveguide gratings (AWG's) for multiplexing and demultiplexing multiple wavelength channels in a DWDM system. Although this is generally perceived as a single-function device, it can be performing the function of more than 100 discrete fiber-optic components and already represents a considerable degree of integration. Furthermore, programmable functions such as variable-optical attenuators (VOAs) and switches made with compatible PLC technology are now moving into commercial production. In this paper, we present results on the integration of active and passive functions together using PLC technology, e.g. a 40 channel AWG multiplexer with 40 individually controllable VOAs.
Single-mode optical waveguides based on planar silica have found increasing application in passive optical components such as arrayed waveguide gratings (AWG), couplers, and splitters. Key aspects of these devices are their low insertion losses and relative insensitivity to temperature. Planar polymer waveguides present a complementary technology that is finding deployment in thermally activated components such as thermo-optic switches, variable attenuators and tunable filters. This results from the large thermo-optic effects and low thermal conductivities in polymers that lead to low power, compact and rapid thermal activation. However, the widespread deployment of planar polymer waveguides has been slowed by inability of single-mode polymer waveguides to achieve the low waveguide losses that have been attained in planar silica. In this paper we look at the sources of loss in polymer optical waveguides, assess approaches to reducing losses, and discuss several important loss measurement techniques valuable for evaluation of new polymer materials.
In view of realizing integrated optic components based on effects such as electro-optic, chi(2):chi(2) cascading, stimulated emission,... one has to first synthesize materials with the proper functionality; this may be achieved by doping solid state matrices by the appropriate organic chromophores. Second, and as important, these materials have to be properly structured into the final optical guiding structures. We shall report on issues related to the realization of chromophore-doped planar waveguides as well as channel waveguides. These structures were realized by either photo-transformation such as photo- chromism and photo-bleaching or reactive ion etching technique, starting with chromophore doped sol-gel materials at high loading contents for which optical index may be controlled via the local dopant concentration. With these materials and techniques, waveguides and components characterized by propagation losses of the order of a cm-1, measured off the edge of the absorption band of the doping species, were fabricated. In order to be also able to study and use waveguide functionalized with low concentration of chromophore species, we developed new sol-gel materials of high optical index, yet low temperature processed. These new films are under study to evaluate their potential as host for organic doped waveguides devices.
Polymeric optical planar waveguide devices such as optical switches, optical arrayed-waveguide grating (AWG) multiplexer/demultiplexer, optical add/drop multiplexer are promising for both of optical WDM networks and access network. For investigating such polymer devices, new polymeric waveguide materials were developed and different polymer integrated optical devices including interferometric-type optical switches, digital-optical switches (DOS), hybrid polymer/silica vertical coupler switches (VCS), polymer AWG multiplexer and athermal all- polymer AWG multiplexer have been studied.
Organic polymers are increasingly attractive alternatives to inorganic materials in telecommunication devices. Polymers offer flexibility, low cost fabrication and connection, high transparency in the visible and near-infrared spectra, and versatility in structure, properties, and grades for task specific integration such as local-area-network applications. Halogenated polymers in particular show negligible transmission losses in the range desired and fluoropolymers represent the lowest loss examples of organic polymers to date. However, commercial perfluoropolymers in general are limited by poor processability, non-trivial refractive index matching, and they typically do not exhibit the thermal and thermomechanical stability required for some commercial processes and extreme environment in-use applications. Our strategy has focused on the thermal cyclopolymerization of trifunctional and bifunctional aryl trifluorovinyl ether monomers to perfluorocyclobutane (PFCB) copolymers. PFCB polymers and copolymers enjoy a unique combination of properties well suited for optical applications such as high temperature stability, precisely controlled refractive index, low moisture absorption, excellent melt and solution processability, a high thermooptic coefficient, and low transmission loss at 1300 and 1550 nm. Copolymerization reactions offer tailored thermal and optical properties by simple choice of comonomer. PFCB polymers can be solution or melt microfabricated via standard methods and can also be processed by soft-lithography techniques. Polymerization and processing parameters and characterization including thermal properties (Tg = 120-350 degree(s)C), optical loss (< 0.2 db/cm at 1550 nm), refractive index tunability (1.449-1.508 at 1550 nm), low birefringence, and optical stability is presented.
Recently, photonic networks based on wavelength division multiplexing (WDM) systems have developed considerably in response to the explosive growth of the Internet. Devices with novel functions are required for photonic networks, and planar lightwave circuits (PLCs) are being considered to meet this need. This paper reports recent progress on PLC- type devices with advanced functions developed for the photonic networks. We describe fabrication techniques and device applications for silica and silicone polymer based PLC technologies.
The rapid growth of communication continuously demands an increasing number of data transport channels. We present an approach towards a substantial growth of channel numbers within the integrated optical waveguide chip. This is accomplished by introducing a vertical integration scheme, which is implemented with stacked polymer waveguides. To meet the requirements of stacked optical waveguide devices concerning index distributions, cross-sections and alignment precision, a novel fabrication technology has been developed. During the stacking process several fundamental problems, e.g., index inhomogenities caused by diffusion effects and distortion of the desired waveguide structures with increasing stack height, have to be avoided. In addition, the non-linear index change of the polymer materials during polymerization has to be carefully considered to come to well defined index distributions, which are the same in all layers. A solution meeting these requirements is presented using standard processes like UV patterning in combination with thermal curing steps.
A hybrid multibeam module using optical waveguides has been developed for laser scanning optics. The module is constructed using hybrid electrical/optical integration technology. Waveguides and laser diodes are assembled on a silicon substrate on which emitted beams from the laser diodes are coupled into waveguides. For the shorter 780 nm wavelength, which is used for this module, the precision of position control for laser diodes and waveguides must improve below 1 micrometers . The polyimide waveguides, which are suitable for mass production, are used. It is confirmed that the multibeam module consisting of a beam divergence angle from 10 degrees to 20 degrees, spatial beam interval with a 12-micrometers minimum, and a large number of the beams is possible.
Proc. SPIE 4439, Integration of organic electroluminescent diodes and polymeric waveguide devices: characterization of light source for optical integrated circuit, 0000 (6 November 2001); doi: 10.1117/12.447624
We fabricated organic electroluminescent diodes (OELD) for use as an light source for optical interconnect in data communication systems. The OELDs consists of indium-tin-oxide (ITO) coated substrates, hole-transporting layer of (alpha) -NPD (4,4'-bis[N-(naphthyl)-N-phenyl-amino]-biphenyl) emissive layer of rubrene (5,6,11,12-tetraphenylnaphthacene) doped Alq3 (8-hydroxyquinoline aluminum) and silver containing magnesium cathode. The OLED was fabricated by deposition deposition technique. These OELDs, with an emission peak center at 560 nm, was fabricated with a vacuum deposition technique. The optical pulses of faster than 30 Mb/s have been generated from the OELD. We discuss the emission characteristics and the pulse response characteristics of the OLED as regards it use as a light source for polymeric waveguides.
The erbium doped waveguide amplifier (EDWA) provides the benefits of high gain per unit length and compact size. We use the erbium two-level system model with the measured material properties and waveguide properties to study the amplifier performance dependence on operating conditions and EDWA lengths. We have established a modeling, simulation, and designing framework to systematically study the amplifier performance issues from materials to device packaging. Simulations of two EDWA examples based on alumino-silicate and phosphate glasses are carried out in detail.
We study the resonant excitation of the electromagnetic modes in a planar waveguide of metallic walls - light incident on the guide from the air can transfer energy through the walls exciting normal modes of propagation. It is found theoretically that radiation propagates along the guide while the reflectivity presents a minimum. The energy of the incident radiation can be transferred to the guide almost completely when the thickness dm of the metallic wall is around two times the skin depth. Experimental evidence of the injection of light is presented for the system Ag/Al2O3/Ag that was grown by pulsed laser deposition.