This PDF file contains the front matter associated with SPIE Proceedings Volume 8613, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

Nanoparticles of noble metals show localized surface plasmon resonance. Plasmon resonances which are collective oscillations of conduction electrons give rise to the enhancement of electromagnetic field to the local surface of metallic nanoparticles. Therefore, various plasmonic near-field lithography systems were proposed so far. Here, we report on a plasmon-assisted nanolithography used for the fabrication of nano-patterns with nanometric accuracy. The lithography system can form deep nano-patterns on positive photoresist film using scattering component of multipole plasmon resonances as an exposure light. Two-photon-induced reaction of a photoresist enabled the formation of fine patterns even using plasmonic scattering light.

A combination of electron- and ion-beam lithographies has been applied to fabricate patterns of plasmonic nanoparticles having tailored optical functions: they create hot-spots at predefined locations on the nanoparticle at specific wavelengths and polarizations of the incident light field. Direct inscribing of complex chiral patterns into uniform nano-disks of sub-wavelength dimensions, over extensive 20-by-20 μm² areas, is achieved with high fidelity and efficiency; typical groove widths are in 10-30 nm range. Such patterns can perform optical manipulation functions like nano-tweezing and chiral sorting. Fabrication procedures can be optimized to pattern thin 0.1-2.5 μm-thick membranes with chiral nanoparticles having sub-15 nm grooves. Peculiarities of optical force and torque calculations using finite-difference time-domain method are presented.

The patterning of colloidal quantum dots with nanometer resolution is essential for their application in photonics and plasmonics. Several patterning approaches, such as the use of polymer composites, molecular lock-and-key methods, inkjet printing, and microcontact printing of quantum dots, have limits in fabrication resolution, positioning and the variation of structural shapes. Herein, we present an adaptation of a conventional liftoff method for patterning colloidal quantum dots. This simple method is easy and requires no complicated processes. Using this method, we formed straight lines, rings, and dot patterns of colloidal quantum dots on metallic substrates. Notably, patterned lines approximately 10 nm wide were fabricated. The patterned structures display high resolution, accurate positioning, and well-defined sidewall profiles. To demonstrate the applicability of our method, we present a surface plasmon generator elaborated from quantum dots.

Electron-beam-induced deposition (EBID) is a gas-phase direct-write technique capable of sub-10 nm resolution, with applications in micro- and nanoscale object manipulation, mask repair, and circuit edit. While several high purity materials can be deposited by EBID, the majority of deposits suffer from undesirable co-deposition of organic or inorganic ligands. As a result, impurity incorporation limits EBID application in processes requiring high purity. Recently, a complimentary technique known as liquid phase EBID (LP-EBID) has been shown to drastically improve deposit purity by utilizing precursors without carbon or phosphorous based architectures. Here we demonstrate direct-write deposition of silver nanostructure arrays, with tunable geometry for localized surface plasmon resonance (LSPR) control. Nanoparticle arrays with 55 – 100 nm diameters were obtained. Resonant wavelengths between 550 - 600 nm were achieved and correlated to the observed nanoparticle geometry. These results demonstrate how LP-EBID can be used to provide site-specific deposition for plasmonic devices and additionally open the door to fields inaccessible to traditional gas-phase EBID.

Direct laser writing is widely used to fabricate 3D waveguide devices by modi cation of a materials refractive index. The fabrication delity depends strongly on focal spot quality, which in many cases is impaired by aberrations, particularly spherical aberration caused by refractive index mismatch. We use adaptive optics to correct aberration and maintain fabrication performance at a range of depths. Adaptive multifocus methods are also shown for increasing the fabrication speed for single waveguides.

A combination of deposition strategies was applied in order to synthesize Au nanoparticle chains embedded in helical Al₂O₃ nanotubes (“nanopeapods”). Carbon nanocoils were grown by chemical vapour deposition and coated with Au by sputtering with a subsequent Al₂O₃ coating by atomic layer deposition. Rayleigh instabilities were made use of in order to fragment the Au coating into nanoparticles with a sharp size distribution. The pitch of the nanocoils arising from three-dimensional periodical topography of the carbon nanocoil templates induced a regular spacing between the nanoparticles. The nanoparticle chains show a strong plasmonic resonance behaviour visible as clear polarization contrast at red wavelengths, which is absent in the blue upon excitation with a confocal laser scanning microscope. The fabricated nanopeapods are suggested promising candidates for highly efficient, ultrathin waveguides.

Guided mode resonance (GMRF) phenomena occurs when the evanescent orders of a diffraction grating are coupled to the waveguide modes and propagate out at given optical parameters such as wavelength, angle, and state of polarization of incident light. The outcoupling field from a waveguide is, in general, polarization sensitive. Polarization insensitive 1D subwavelength grating structures with high diffraction efficiency at normal and oblique incidence are required, for example, in optical communications where output light may possess any polarization state. This means that an s- or p-polarized input optical field, which generally couples TE- or TM-modes in the waveguide under different resonance conditions, can be tuned at one resonance by selecting suitable grating parameters, regardless of the input polarization state. All of the polarization insensitive devices fabricated to date either employing a method which is not cost-effective or simple enough to some extent. In this work, we report the design and fabrication of two types of non-polarizing binary-structured onedimensional (1D) GMRF at normal incidence. A single layer binary-profile TiO₂ resonant grating (grating-I) is fabricated by Atomic layer deposition (ALD), electron beam lithography (EBL) and reactive ion etching (RIE), which demonstrates almost perfect non-polarizing filtering effect with 1D grating under normal incidence. A double layer rectangular-profile polycarbonate-TiO₂ 1D GMR grating (grating-II) is fabricated by nanoimprint lithography (NIL) and ALD which also shows good non-polarizing property and the potential of cost-effective mass fabrication of such functional devices.

Normally, the larger refractive index contrast of silicon-on-insulator (SOI) photonics used for transporting highly confined optical modes is not available in compound semiconductor systems because the optically active layer rests upon an epitaxial support layer having a similar refractive index. Here, a semiconductor-under-insulator (SUI) technology for compound semiconductor membrane photonic circuitry is presented. It will be shown that such a technology can facilitate the transport of highly confined optical modes in compound semiconductor systems and is anticipated to be a critical part of future scalable quantum photonics applications.

Oblique angle metal deposition has been combined with high aspect ratio imprinted structures to create wire grid polarizers (WGP’s) for use as polarization recyclers in liquid crystal displays. The optical results for the oblique deposition WGP show contrast comparable to a conventionally etched WGP. In addition, the WGP showed improved spectral and spatial uniformity as compared to a multilayer reflective polarizer. The next steps to the fabrication of meter sized WGP are proposed.

Versatility of femtosecond direct laser writing (DLW) technique for non-destructive and reversible micro-structuring of lithium niobate crystals is demonstrated. Persistent photorefractive modification induced by the focused laser beam without structural damage to the host crystal has refractive index modulation on the order of 10^-5-10^-2, and can be optically erased or modified. Application of this mechanism for realization of diffractive optical elements is demonstrated.

The metrology of mirrors with an off-axis aspheric or freeform shape can be based on optical testing using a Computer Generated Hologram as wavefront matching element in an interferometric setup. Since the setup can be understood as optical system consisting of multiple elements with six degrees of freedom each, the accuracy strongly depends on the alignment of the surface under test with respect to the transmission element of the interferometer and the micro optics of the CGH. A novel alignment approach for the relative positioning of the mirror and CGH in six degrees of freedom is reported. In the presented work, a proper alignment is achieved by illuminating alignment elements outside the Clear Aperture (CA) of the optical surface with the help of auxiliary holograms next to the test CGH on the substrate. The peripheral holograms on the CGH substrate are used to generate additional phase maps in the interferogram, that indicate positioning errors. Since the reference spheres represent the coordinate system of the mirror and are measured in the same precision as the optical surface, the registration and shape has to be appropriate to embody the mirrors coordinate system. The alignment elements on the mirror body are diamond machined using freeform turning or micro milling processes in the same machine setup used for the mirror manufacturing. The differences between the turning and milling of alignment lenses is discussed. The novel approach is applied to correct the shape error of a freeform mirror using ultra precision machining. The absolute measurement of the quality of freeform mirror shapes including tilt and optical power is possible using the presented alignment concept. For a better understanding, different metrology methods for aspheres and freeforms are reviewed. To verify the novel method of alignment and the measurement results, the freeform surface is also characterized using ultra high accuracy 2½D profilometry. The results of the different techniques for the absolute measurement of freeforms are compared.

We demonstrated a 45 degree micro mirror by a direct laser writing method. A flat, smooth and clearly defined mirror surface has been fabricated despite of the finite size and long tail of the point spread function of the exposure tool.

Surface-enhanced Raman scattering (SERS) allows the detection of sub-monolayer adsorbates on nanostructured metal surfaces (typically gold or silver). The technique has generated interest for applications in biosensing, high-resolution chemical mapping and surface science. SERS is generated by the localized surface plasmon resonance that occurs when the nano-metal is exposed to laser light. These plasmonic effects rely on features as small as ~1 nm, which poses a challenge for the fabrication of sensitive and reproducible substrates. Consequently a wide range of nanofabrication techniques have been used to make SERS substrates. Further challenges are encountered when transferring wafer-scale techniques to the tips of optical fibers in order to produce devices for in vivo SERS sensing. Here we describe fiber tip substrates based on miniaturization by fiber drawing, physical vapor deposition and nanoimprint lithography. Despite recent progress, the fabrication of sensitive, reproducible and affordable SERS fiber sensors remains an unresolved problem.

Abstract: Here we present holographic fabrications of large area nano-optical device templates, including nano-antenna and photonic quasi-crystals using a single reflective optical element (ROE) through single beam and a single exposure process. These ROEs consist of several silicon wafers arranged with 5 or 6-fold symmetry, supported by two plastic platforms. By changing the polarization of the incident beam, various photonic quasi-crystal including spiral quasicrystals can be fabricated using the 5-fold symmetrically arranged optical element. Using the single optical element with silicon chips arranged in 6-fold symmetry, large areas of nano gap arrays can be fabricated holographically. These nanogaps and their shapes can be controlled through the phase delay of one laser beam. The nano gap arrays will be used for fabrication of nano-antennas arrays after metal depositions.

Opalux’s P-Ink material represents a revolutionary step forward in display technology, offering the ability to reflect bright and vivid colors spanning the visible spectrum. By applying low power electric pulses, the color of this Photonic Color-based material can be selected at will, with the resulting electrically bi-stable color states requiring no power to maintain. It can be coated onto rigid and flexible substrates in scale, highlighting its potential to drive the development of bendable form factors for displays.

Microstructured Optics enable a new class of optics - new in terms of enabling functionality that has not been achieved so far, as well as in terms of reducing size while increasing performance of existing solutions significantly. In modern optics several demands exist for implementing microstructured optical components. For example, diffractive optical elements (DOEs) are of considerable advantage in combination with refractive lenses to form so-called hybrid optical systems. The inverse chromatic dispersion of diffraction in contrast to refraction opens new possibilities for the compensation of chromatic aberrations. Furthermore, the realization of a diffraction grating on a concave optical surface allows the functional integration of imaging and dispersing in one single optical component, which is a key enabler for miniaturization of spectroscopic systems. In the sophisticated illumination systems microstructured beam shaping elements play an essential role. Micro- and nanostructures in the subwavelength range open alternative solutions for antireflective properties and polarization management.

Photonic integration has witnessed tremendous progress over the last years, and chip-scale transceiver systems with terabit/s data rates have come into reach. However, as on-chip integration density increases, a technological breakthrough is considered indispensable to cope with the associated off-chip connectivity challenges. Here we report on the concept of photonic wire bonding, where transparent waveguide wire bonds are used to bridge the gap between nanophotonic circuits located on different chips. We demonstrate fabrication of three-dimensional freeform photonic wire bonds, and we experimentally confirm their viability for broadband low-loss coupling and multi-terabit/s data transmission.

By using focused ultrashort pulsed laser radiation refractive index modifications are induced in glass in order to generate optical components. The understanding of physically fundamental processes induced by laser radiation is the basis for the systematic control and maximization of the refractive index change for the realization of three-dimensional, optical components for integrated optics like in-volume waveguides. In this paper fundamental processes which are induced by focused laser radiation in the volume of borosilicate glass D263 and fused silica are investigated. The glass materials are structured by laser radiation in the infrared spectral range (λ=1045nm). By using femtosecond laser pulses with high repetition rates (f = 500 kHz), thermal processes like heat accumulation effects are induced leading to heat affected zones and thus waveguide cross sections with dimensions larger than the focal spot. The absorptivity during modification in relation to the applied pulse energy is measured for different repetition rates in both glass materials. Furthermore, the laser induced structural change in the glass matrix by the increase of three- and four-membered ring structures is proved with Raman spectroscopy.

Two photon polymerization (TPP) lithography has been established as a powerful tool to develop 3D fine structures of polymer materials, opening up a wide range applications such as micro-electromechanical systems (MEMS). TPP lithography is also promising for 3D micro fabrication of nanocomposites embedded with nanomaterials such as metal nanoparticles. Here, we make use of TPP lithography to fabricate 3D micro structural single wall carbon nanotube (SWCNT)/polymer composites. SWCNTs exhibit remarkable mechanical, electrical, thermal and optical properties, which leads to enhance performances of polymers by loading SWCNTs. SWCNTs were uniformly dispersed in an acrylate UV-curable monomer including a few amounts of photo-initiator and photo-sensitizer. A femtosecond pulsed laser emitting at 780 nm was focused onto the resin, resulting in the photo-polymerization of a nanometric volume of the resin through TPP. By scanning the focus spot three dimensionally, arbitrary 3D structures were created. The spatial resolution of the fabrication was sub-micrometer, and SWCNTs were embedded in the sub-micro sized structures. The fabrication technique enables one to fabricate 3D micro structural SWCNT/polymer composites into desired shapes, and thus the technique should open up the further applications of SWCNT/polymer composites such as micro sized photomechanical actuators.

We report on the fabrication of a light sensitive waveguide via vacuum assisted microfluidic (VAM) soft lithographic technique. UV curable light insensitive waveguides function like typical polymer waveguides with desired mode confinements while the light sensitive waveguides formed by an azobenzene based polymer resin can achieve refractive index modulation through green or blue laser illumination. The refractive index modulation is instant and reversible in the light sensitive waveguide. The VAM technique is used for the fabrication of multisection waveguides using different resins at the same time which is unique compared to conventional single material waveguide fabrication. The effective fabrication of various waveguide sections with the light sensitive azobenzene based UV curable resin can result in many functional waveguide devices for photonics applications.

Conductive polymers with high solids loading (> 40wt.%) are challenging to pattern to single micron feature sizes and require unique techniques or templates to mold the material. The development of a conductive polymer optical tag is discussed for identifying the presence of hydrofluoric acid (HF) and leverages free standing silicon fins as a template utilizing deep reactive ion etching (DRIE) techniques will be discussed. This work is aimed towards a future flexible conductive polymer tag to be transferred via adhesive or epoxy for a novel sensor surface. The advantage to this technique over wafer thinning is a higher throughput of device manufacture without damage to the silicon fins or polymer due to chemical-mechanical interactions or added protective layers. The gratings consist of a high spatial frequency (1.15 μm pitch) grating consisting of lines of conductive polymer and lines of silicon which are free standing. A novel running bond pattern aims to minimize the intrinsic stress and allows the conductive polymer to infiltrate without distorting the template. The polymer conductivity mechanism has been designed to break down under a chemical binding to fluorine; changing its conductivity upon exposure, and results in a change in the polarization response. The use of the polarization response makes the signal more robust to intensity fluctuations in the background or interrogation system. Additionally, the use of optical interrogation allows for standoff detection in instances where hazardous conditions may be present. Examples of material and device responses will be shown and directions for further investigation are discussed.

Designing and integrating micro-optical components into atom and ion traps are enabling steps toward miniaturizing trap dimensions in quantum computation applications. The micro-optic must have a high numerical aperture for precise illumination of the ion and should not introduce scatter. Due to the extreme optical efficiency requirements in trapped ion and atom-based quantum information processing, even slight losses from integrated micro-optics are detrimental. We have designed and fabricated aspheric micro-lenses through grayscale transfer into a fused silica in an effort to realize increased transmissive efficiency and decreased scatter compared to an equivalent diffractive optical element. The fabricated grayscale lens profile matched the desired lens profile well, and the measured and predicted optical performances were in good agreement. The pattern was transferred via coupled plasma reactive-ion etching smoothly into the fused silica with a RMS roughness ~ 35 nm. The micro-lens had a diameter of 88 um and 14.2 um sag, with an as-designed focal length of 149 um and spot diameter of 2.6 um. The maximum measured efficiency was ~80% (86% of theoretical, possibly due to rms roughness). This realized efficiency is superior to the equivalent diffractive lens efficiency, designed to the same use parameters. The grayscale approach demonstrated an increase in collection efficiency, at the desired optical focal length, providing the potential for further refinement.

Although the potential of spectral imaging has been demonstrated in research environments, its adoption by industry has so far been limited due to the lack of high speed, low cost and compact spectral cameras. We have previously presented work to overcome this limitation by monolithically integrating optical interference filters on top of standard CMOS image sensors for high resolution pushbroom hyperspectral cameras. These cameras require a scanning of the scene and therefore introduce operator complexity due to the need for synchronization and alignment of the scanning to the camera. This typically leads to problems with motion blur, reduced SNR in high speed applications and detection latency and overall restricts the types of applications that can use this system. This paper introduces a novel snapshot multispectral imager concept based on optical filters monolithically integrated on top of a standard CMOS image sensor. By using monolithic integration for the dedicated, high quality spectral filters at its core, it enables the use of mass-produced fore-optics, reducing the total system cost. It overcomes the problems mentioned for scanning applications by snapshot acquisition, where an entire multispectral data cube is sensed at one discrete point in time. This is achieved by applying a novel, tiled filter layout and an optical sub-system which simultaneously duplicates the scene onto each filter tile. Through the use of monolithically integrated optical filters it retains the qualities of compactness, low cost and high acquisition speed, differentiating it from other snapshot spectral cameras based on heterogeneously integrated custom optics. Moreover, thanks to a simple cube assembly process, it enables real-time, low-latency operation. Our prototype camera can acquire multispectral image cubes of 256x256 pixels over 32 bands in the spectral range of 600-1000nm at a speed of about 30 cubes per second at daylight conditions up to 340 cubes per second at higher illumination levels as typically used in machine vision applications.

The highly sensitive photoluminescence (PL) response of group III-Nitrides (III-N) nanowire heterostructures (NWHs) to hydrogen (H₂) and oxygen (O₂) allows for the realization of reliable gas detectors. For industrial real time gas monitoring applications, e.g. in the field of aerospace, a large scale laboratory setup was miniaturized by integrating electro-optical components and the NWHs within a robust micro optical system. As a result of the all optical addressing and read out the detection periphery can be completely isolated from the investigated environment which significantly increases the detection sensitivity. The optical design and fabrication techniques as well as an experimental investigation of the system performance are the main topics discussed in this paper.

The combination of HgCdTe detectors and Fabry-Pérot filters (FPFs) is highly desirable for hyperspectral detection in the infrared band over a broad wavelength range. The results of comprehensive modeling of distributed- Bragg-reflector-based tunable FPFs that can be used with HgCdTe array detectors for hyperspectral imaging modules are presented, focusing on the impact of FPF non-idealities on optical performance. The effects of surface and interface roughness on the spectral resolution and transmissivity of the cavity was explored to determine if certain thin film deposition techniques are suitable to economically fabricate FPFs. The impact of varying field-of-view (FOV) and incident angles are also discussed. Finally, the impact of FPF bowing on spectral resolution is discussed.

Micro lens arrays (MLA) can be utilized in various applications of light sensitive devices such as digital cameras or objective free microscopes, and 3D imaging because of their good light collection efficiencies. Many of the fabrication methods used today require heat or expensive equipment or molds and that is why there is a need for a simple and cost effective fabrication method for MLAs. An inkjet printing based production method for low-cost micro lenses is presented here. By pre-patterning the used substrate the printing accuracy and the shape of the lenses is improved. The surface patterning is done with photolithography to fabricate round, shallow reservoirs for the lenses to be printed in. The liquid lens material is then inkjet printed into them. The pattern edges prevent the spreading of the ink outside the wanted area increasing the tolerance for printing inaccuracy and resulting to the uniform array of micro lenses. By depositing the ink to the reservoir, the ink forms a convex surface a.k.a. a lens. The used lens material is negative photoresist, so after printing it is cured with UV-light and baked in a hot plate to solidify the lens matrix. By placing different amount of ink in a reservoir the height of the lenses changes and thus the focus of the lens can be adjusted making the proposed method versatile tool for MLA fabrication.

Here we report Direct Laser Writing (DLW) based fabrication of aspheric microlenses out of hybrid organicinorganic photopolymer ORMOSIL. Using the advantages of the flexible manufacturing technique the produced microlenses are embedded inside a fluidic channel. Applying the soft-lithography molding technique the structures are transferred to the elastomer PDMS and hydrogel PEG-DA-258 materials. Measurements show that such replica transferring can reproduce the initial structures into other materials on desired substrates with no noticeable losses of quality. Furthermore, it makes femtosecond laser redundant once the original structure is made. The embedded structures are immersed into several liquid media (acetone, methanol) and the focusing performance corresponding to the change of the optical path length of the microlenses is obtained. It well matches with the estimated values. In conclusion, we report a combination of laser fabrication and replication methods as an efficient way to produce optofluidic components, which can be used for light based sensing, trapping or other applications such as MOEMS devices.

For many applications it is inevitable to protect MEMS devices against environmental impacts like humidity which can affect their performance. Moreover recent publications demonstrates that micro mirrors can achieve very large optical scan angles at moderate driving voltages even exceeding 100 degrees when hermetically sealed under vacuum. While discrete chips may be evacuated and sealed on single die level using small can packages like TO housings, it is obvious that for high volume production a much more economical solution for the realisation of transparent optical packages already on wafer level must be developed. However, since any laser beam crossing a transparent glass surface is partly reflected even when anti-reflective coatings are applied, the construction of a wafer level optical housing suitable for laser projection purpose requires more than the integration of simple plane glass cap. The use of inclined optical windows avoids the occurrence of intense reflections of the incident laser beam in the projected images. This paper describes a unique technology to fabricate glass packages with inclined optical windows for micro mirrors on 8 inch wafers. The new process uses a high temperature glass forming process based on subsequent wafer bonding. A borosilicate glass wafer is bonded together with two structured silicon wafers. By grinding both sides of the wafer stack, a pattern of isolated silicon structures is defined. This preprocessed glass wafer is bonded thereon on a third structured silicon wafer, wherein the silicon islands are inserted into the cavities. By setting a defined pressure level inside the cavities during the final wafer bonding, the silicon glass stack extruded and it is out of plane during a subsequent annealing process at temperatures above the softening point of the glass. Finally the silicon is selectively removed in a wet etching process. This technique allows the fabrication of 8 inch glass wafers with oblique optical surfaces with surface roughness <1 nm and an evenness of < 300 nm.

We present a novel method for the optical fabrication of particular structures with sub-100-nm features by using direct-write laser lithography at 405-nm wavelength. A doughnut-shaped spot, generated by focusing an azimuthally polarized beam using an NA=0.2 lens, exhibits a central dark region, i.e., optical vortex. This is the key to write well-isolated nano-structures like nano-cylinders. A decomposition of such doughnut spots leads to two-half-lobes spots that can create line patterns when linearly scanned. This method is fast and inexpensive to fabricate well-isolated nano-cylinders or nano-holes and nanometer-size line patterns or trenches compared to other nano-fabrication methods. They can find applications for the fabrication of a nano solid immersion lens, an isolated quantum dot, plasmonic waveguides, and for micro- and nano-fluidics.

We report on the light confinement effect observed in non-ideally shaped (i.e., non-spherical) nanoscale solid immersion lenses (SILs). To investigate this effect, nanostructures of various shapes are fabricated by electron-beam lithography. When completely melted in reflow, these non-circular pillars become spherical, while incomplete melting results in nonspherically shaped SILs. Optical characterization shows that non-ideal SILs exhibit a spot size reduction comparable to that of spherical SILs. When the SIL size is wavelength scale or smaller, aberrations are negligible due to the short optical path length. This insensitivity to minor variations in shape implies a large tolerance in nano-SIL fabrication.

In this work, we present the holographic fabrication of woodpile-type photonic crystal templates in photosensitive polymer using a silicon-on-PDMS based reflective optical element. The reflective optical element is fabricated from four silicon chips placed inside a polydimethylsiloxane (PDMS) mold, which reflects a circularly or elliptically polarized beam into four linearly polarized side beams, arranged four-fold symmetrically about a central beam, with electric fields normal to the incident plane, and also reduces the laser intensity of the side beams. With a single beam and a single reflective optical element, we can generate the desired laser beam intensities and polarization of each beam, thereby creating woodpile-type photonic crystal templates, and improving the contrast of 3D structures.

In this paper we show that it is possible using optical photolithography to obtain micron and submicron features for periodic structures in non-contact using the Talbot effect. In order for this effect to work it is important to have good control of the illumination light and here we show that the MO Exposure Optics (MOEO) developed by SUSS MicroOptics provides uniform and well collimated illumination light suitable for Talbot lithography. The MOEO can easily be incorporated into a standard mask aligner. Here we show 1μm and 0.65μm diameter holes in a hexagonal array in photoresist made in large-gap proximity printing.

Traditionally, polymer photonic devices are fabricated using clean-room processes such as photolithography, electron beam lithography, reactive ion etching (RIE) and lift-off methods etc, which leads to long fabrication time, low throughput and high cost. We describe in this paper a novel process for fabricating polymer photonic devices using a combination of imprinting and ink jet printing methods, which provides high throughput on a variety of rigid and flexible substrates with low cost. Particularly, we demonstrate a thermo-optic switch and an electro-optic modulator. In the rib waveguide patterning, the imprint lithography transfers the waveguide pattern from a soft mold to UV-15LV bottom cladding layer. The soft mold is replicated from a silicon master mold and rendered hydrophobic to ensure successful de-molding. Ink jet printing method is used to deposit the core layer in thermo-optic switch and electrode layers in electro-optic modulator. Compared to spin-coating method, the use of print-on-demand method greatly reduces material consumption and process complexity. Every step involved has the potential to be fully compatible with roll-toroll (R2R) volume production. For example, the soft mold can be wrapped around a cylinder to realized roll-to-roll imprinting. By combining R2R imprint lithography with ink jet printing, fabrication of large volume and large area multi-layer polymer photonic devices can be realized.

Moxtek has developed a high contrast IR polarizer on silicon suitable for long wavelength thermal IR applications using our aluminum nanowire, large area patterning capabilities. Between 7 and 15 microns, our 144 nm pitch polarizers transmit better than 70% of the passing polarization state and have a contrast ratio better than 40 dB. Transmission and reflectance measurements were made using a Fourier Transform Infrared (FTIR) spectrometer with instrument accuracy verified using silicon and germanium reference standards. Results were compared to RCWA modeling of the wire grid polarizer (WGP) performance on antireflection-coated wafers. The FTIR instrument noise floor limited the maximum contrast measurement to about 40 dB, but high polarizer contrast was verified at 10.6 μm using a CO₂ laser and pyroelectric detector. A continuous wave Gaussian beam from a CO₂ laser was used for Laser Damage Threshold (LDT) testing and showed LDT values of 110 kW/cm² and 10 kW/cm² in the blocking and passing states respectively. Analysis of laser damage threshold test samples shows the damage propagating from defects in the anti-reflection (AR) coating. Removing these AR coating defects should improve LDT performance and transmission in the thermal IR.

Driven by the demand of miniaturized and highly integrated functionalities in the area of photonics and photonic circuits, the metal or plasmon optics has become a promising method for manipulating light at the nanometer scale. Especially the application of periodic sub wavelength hole structures within an opaque metal film on a dielectric substrate holds many advantages for the realization of optical filters, since the variation of the hole diameter and the periodicity allows a selective filter response. This paper is concerned with the modeling, fabrication and characterization of a sub wavelength hole array for surface plasmon enhanced transmission of light [1]. The theoretical backgrounds as well as the basics of the simulation by Finite-Difference Time-Domain (FDTD) are described for the target structure with a hole diameter of 180 nm and a periodicity of 400 nm. By using a double-molding technology via nanoimprint lithography the fabrication of this sub wavelength hole array with a peak wavelength of 470 nm and full width at half maximum of 50 nm from a silicon nanopillar master is demonstrated. In order to ensure the dimensional stability of the molded structures, characterization was consequently done by means of a self made non-contact mode atomic force microscope.