We describe the state of the art in optoelectronic component integration, and the current degree of commercial deployment of integrated optoelectronics as dictated by the balance of market pull and technology push. We also present the long-term outlook for optoelectronic integration, including the drivers and barriers that set the roadmap toward the optoelectronic ULSI. We discuss an optoelectronic integration platform that utilizes organic and inorganic materials for the hybrid integration of passive and active optical elements.

This paper reviews design considerations pertinent to amorphous silicon (a-Si:H) thin film transistor (TFT) based drive circuits for active matrix organic light emitting diode (AMOLED) displays. Critical design and performance issues related to the a-Si:H TFT are described along with the optimisation of pixel circuit parameters for high lifetime, low power, high resolution, and high frame rate AMOLED displays.

Over the years, Field Programmable Gate Arrays (FPGAs) have made a profound impact on the electronics industry with rapidly improving semiconductor-manufacturing technology ranging from sub-micron to deep sub-micron processes and equally innovative CAD tools. Though FPGA has revolutionized programmable/reconfigurable digital logic technology, one limitation of current FPGA’s is that the user is limited to strictly electronic designs. Thus, they are not suitable for applications that are not purely electronic, such as optical communications, photonic information processing systems and other multi-technology applications (ex. analog devices, MEMS devices and microwave components). Over recent years, the growing trend has been towards the incorporation of non-traditional device technologies into traditional CMOS VLSI systems. The integration of these technologies requires a new kind of FPGA that can merge conventional FPGA technology with photonic and other multi-technology devices. The proposed new class of field programmable device will extend the flexibility, rapid prototyping and reusability benefits associated with conventional electronic into photonic and multi-technology domain and give rise to the development of a wider class of programmable and embedded integrated systems. This new technology will create a tremendous opportunity for applying the conventional programmable/reconfigurable hardware concepts in other disciplines like photonic information processing. To substantiate this novel architectural concept, we have fabricated proof-of-the-concept CMOS VLSI Multi-technology FPGA (MT-FPGA) chips that include both digital field programmable logic blocks and threshold programmable photoreceivers which are suitable for sensing optical signals. Results from these chips strongly support the feasibility of this new optoelectronic device concept.

The holographic-grating based wavelength-controlled true-time-delay devices are presented in the paper. The optical true-time-delay can be continuously controlled by continuously tuning the wavelength of a single laser within the devices. The dispersion ability of the devices is greatly enhanced by increasing the diffraction angles of the holographic gratings. The fabricated true-time-delay devices work within 1550nm region. The loss performance of the devices were calculated and measured. The wavelength-controlled true-time-delay was also characterized both theoretically and experimentally.

Nano optical biosensors employ the interaction between biomolecules and light confined in nanometer scale structures to report the bio-recognition events. This small scale sensing area/volume can ensure that small amount of biorecognition events could be detected. The exceptional sensitivity and high spatial density of nano optical biosensors make them unique in practical applications in nucleic acid detection. Lab-on-a-Chip systems provide the capabilities of separation, cell lysing, polymerase chain reaction (PCR), allowing finishing bio agent detection processes on a chip. In this paper, we present our recent efforts on integrating some novel nanooptical biosensors into Lab-on-a-Chip systems and some preliminary test results.

Commercial Raman confocal microscopy can acquire images with a resolution down to 200 nm. Much effort has recently been devoted to improve upon this resolution and obtain chemical characterization of ultimately a single organic molecule. As an effort in this direction, we have developed an experimental configuration by combining the analytical power of Raman spectroscopy with the nanometer resolution of atomic force microscopy (AFM). Here, an AFM silicon nitride probe, coated with a 40 nm silver layer, was used to significantly enhance the Raman signal by laser excitation of surface plasmons in the tip coating. Experimental results indicate a local surface enhanced Raman scattering (SERS) increase of 10⁵. Lateral scanning of the sample and collecting the SERS signal allows for a 2D image of the chemical identity of the probed sample simultaneous with its topography as measured by the AFM. Also, the ratio of Stokes to anti-Stokes can be used to obtain an instantaneous and absolute map of the local temperature across the sample.

Fast and secure wireless data transmission is a vital component for future military and industrial applications. While currently existing RF solutions can provide wireless data communications, this approach is limited by lack of information security and significantly reduced data bandwidth when a large number of communications channels are needed. Based on the commercial success of optical telecommunications technology, it has been suggested that optoelectronics could provide a viable wireless communications technology. In contrast to the commercial telecom industry, which uses optical fiber-based communications channels, an optical wireless communication system utilizes free space optical paths to communicate data. It should be noted that the IR remote used in consumer electronics is essentially a single channel version of this systems that is only suitable for relatively short communication distances (i.e. less than 10m). The extension of this technology to a system capable of supporting multiple optical transmitters working over longer distances has been a significant challenge. The realization of such a free space optical wireless communication system is dependent on the development of a photoreceiver array technology capable of tracking the spatial location of multiple communication transmitters. Similar to commercially available image capture devices the Data Integrated Video Sensor reported here is capable of collecting data over a large field of view. However, the Photonic VLSI based chip presented here is capable of simultaneously detecting (and tracking) multiple optical communications sources transmitting at data rates that are significantly higher than those achievable with commercial image/video capture devices. Along with a description of the basic operational features of this new optoelectronic device technology, we present here the first working demonstration of a prototype Data Integration Video Sensor chip capable of simultaneously receiving data from two separate optical communication sources. In addition to this experimental verification of the device concept, potential application areas for this new technology will be highlighted.

Embedding of optoelectrical, optical, and electrical functionalities into low-cost products like packages and printed matter can be used to increase their information content. These functionalities make also possible the realization of new type of entertaining, impressive or guiding effects on the product packages and printed matter. For these purposes, components like displays, photodetectors, light sources, solar cells, battery elements, diffractive optical elements, lightguides, electrical conductors, resistors, transistors, switching elements etc. and their integration to functional modules are required. Additionally, the price of the components for low-end products has to be in cent scale or preferably below that. Therefore, new, cost-effective, and volume scale capable manufacturing techniques are required. Recent developments of liquid-phase processable electrical and optical polymeric, inorganic, and hybrid materials - inks - have made it possible to fabricate functional electrical, optical and optoelectrical components by conventional roll-to-roll techniques such as gravure printing, embossing, digital printing, offset, and screen printing on flexible paper and plastic like substrates. In this paper, we show our current achievements in the field of roll-to-roll fabricated, optics, electronics and optoelectronics. With few examples, we also demonstrate the printing and hot-embossing capabilities of table scale printing machines and VTT Electronic's 'PICO' roll-to-roll pilot production facility.

A new technology for performing high-precision Stokes polarimetry is presented. One traditional Stokes polarimetry configuration relies on mechanical devices such as rapidly rotating waveplates that are undesirable in vibration-sensitive optics experiments. Another traditional technique requires division of a light signal into four components that are measured individually; this technique is limited to applications in which signal levels are sufficient that intensity reduction does not diminish the signal-to-noise ratio. A new technology presented here is similar to the rotating waveplate approach, but two liquid crystal variable retarders (LCVR’s) are used instead of waveplates. A Stokes polarimeter instrument based on this technology has been made commercially-available. The theory of operation is detailed, and an accuracy assessment was conducted. Measurement reproducibility was verified and used to produce empirical estimates of uncertainty in measured components of a Stokes vector. Uncertainty propagation was applied to polarization parameters calculated from Stokes vector components to further the accuracy assessment. A calibrated polarimeter measures four Stokes components with 10^-3 precision and average predicted uncertainties less than ±2x10^-3. An experiment was conducted in which the linear polarization angles were measured with a LC polarimeter and with a photodiode for comparison. Observed discrepancies between polarization angle measurements made with a polarimeter and those made with a photodetector were nominally within ±0.3°.

We have developed the all-optical EO-modulator using a pulsed photogalvanic power supply driven by light illumination (coherent and incoherent). Generated by ferroelectric crystal with the photogalvanic effect (Fe-doped LiNbO₃), electrical pulses were used for driving a standard EO-modulator, based on transversal EO effect in Bi₁₂SiO₂₀ (BSO) crystals. Both parallel and serial connections of photogalvanic crystal (LN), BSO and oscilloscope were tested. The depth of EO-modulation was very sensitive to the impedance of the connected cables, which implies the existence of transmission-line resonances. Secondly, a more compact version of EO self-modulation is realized with green (wavelength λ=532 nm, P=100mW) solid-state CW laser. In this case, reflection of the CW laser from the LN crystal was modulated in time. Pulsating optical reflection was correlated with the pulsating electrical signals. We report both modes of operation: (1) as pulsed high-voltage power supply, and (2) as compact-pulsed optical modulator. We have described these pulsations using model of photogalvanic effect and ferroelectric emission.

Distributed temperature sensor based on Raman scattering is investigated. The ratio of intensities in Stokes and anti-Stokes bands reveals the temperature of a fiber section. A spatial resolution of around 1m is obtained by use of Incoherent Optical Frequency Domain Reflectometry. An accuracy of ±2K is demonstrated over a 16km single-mode fiber, which represents a new record. A brief discussion on the choice of the sensing fiber is also given.

We demonstrated a magneto-optic spatial light modulator with one-step pattern formation of iron-garnet films on ion-milled substrates by LPE. The one-step pixel growth is based on the combination of a single-crystal epitaxial film growth (pixel area) by LPE and a impeded film growth (pixel gap area) on a substrate whose surface has been locally damaged and milled by ion bombardment before film deposition. This method overcomes the disadvantages associated with groove etching of the conventional MOSLM. The fabricated prototype MOSLM is switched by applying driving currents of 40 mA for the bottom conductor line and 80 mA for the top conductor line under external bias field of 20 Oe, which is over 2 times smaller than that of the conventional MOSLM. These results strongly suggest that the novel MOSLM can provide higher resolution, simpler fabrication process, more compact systems and lower driving current. Also, the selective-area LPE method offers new possibilities for the fabrication of integrated magneto-optic light switch arrays, magnetic waveguides and similar devices.

In this work we describe an experimental technique to measure the refraction index of the 3M PP2500 film which has good behavior as quarter wave retarder plate for λ=633 nm. This technique is achieved when two perpendicular linearly polarized beam from a Wollaston prism are incident on the thickness of the film. The beams were incident parallel to the fast axis to measure the ordinary refraction index and parallel to the slow axis to measure the extraordinary refraction index. Some experimental results are shown.

An electro-holographic display based on the diffraction specific computation can reduce speckle using electronic diffusion through selective addition of pseudorandom sequence. Intensity fluctuation due to the introduction of pseudorandom noise does not affect 3-D images significantly since spatial windows formed by diffused basis phase sets do not widen noticeably at low spread of the pseudorandom sequence while its features are much smaller than human visual resolution. The result shows crosstalk blur characteristic of substantial variation in the degree of diffusion among basis phase sets. Also, coherent artifacts may be produced by the interference between spatial windows if basis phase sets are sub-optimally designed.

We have proposed a fault-tolerant automatic routing method with two photorefractive double phase conjugate mirrors (DPCMs) for free space optical communication by now. In this method, a signal beam can be all-optically and automatically switched from a main line to a backup line when the main line is shut off by obstacles. The optical link between a transmitter and a receiver is kept without any electronic devices and complex optical configuration because the adequate communication line is automatically selected by two DPCMs which are generated by the signal beam and support beams in one photorefractive crystal. In this report, we equalize the signal beam intensities on the main line and the backup line to increase the reliability of communication. If a coupling strength ratio between two DPCMs is inappropriate, the signal beam intensities on both lines become inequality and this induces the increase of the bit error rate in beam detection. Therefore, it is necessary to adjust the signal beam intensities by changing the coupling strength ratio between two DPCMs. We show that the signal beam intensities on both lines can be equalized completely by using the optimum coupling strength ratio between two DPCMs, e.g. about 1.28 in BaTiO₃ crystal.

We propose an all-optical interconnection with double mutual-pumped phase conjugate mirrors (MPPCM). The bi-directional interconnection is possible by using single MPPCM, however it is difficult to reconfigure the wiring pattern because the incident angle or location of the signal beams must be readjusted to buildup the new communication lines. In our interconnection, the bi-directional connection between channels is formed by the two MPPCMs produced by the illumination of the signal beams and the control beam. Therefore, the wiring pattern can be reconfigured flexibly by changing the spatial distribution of the control beam without any adjustment of the signal beams. In addition, the self-holding of connection can be achieved because the signal beams diffracted by the MPPCM illuminate the other MPPCM and the holograms in MPPCMs are maintained even if the control beam is cut off. It enables the suppression of control beam power consumption. We investigate the connection efficiency of this interconnection in order to estimate the optimum beam splitter reflectivity and intensity ratio of signal beams for obtaining higher connection efficiency and lower coupling strength threshold for the establishment of connection. We also confirm the self-holding of connection experimentally using the BaTiO₃ crystals and the Ar⁺ laser and show that the connection is maintained for several hundred times as long as the time constant of the crystal.

To avoid potential large bending losses, the technique of high index contrast (HIC) has been developed. Silicon-oxynitride possess the priorities of the low residual stress, variations of the refractive index controlled by processing gas, and low absorption phenomena for infrared region, result in excellent promise and can provide key practical devices in dense wavelength division multiplexing (DWDM). The purpose of this study is to investigate and develop the rib shape, detail scale, reasonable selection of the waveguide material for silicon-oxynitride arrayed waveguide grating (AWG) design, processing parameters, and optical properties. Selecting index of 1.50 and 1.45 silicon-oxynitride as core and top/bottom cladding layers with reasonable design parameters represented very low loss, crosstalk, and side-lobe transmission spectral by 2D and 3D simulations. Based on the design results, we will perform the actual device fabrication. Silicon-oxynitride films optical measurements indicated, the refractive index and the extinction coefficient were 1.45~1.89 and 1x10^-4~4.3x10^-4 respectively by varying N₂O/N₂ ratio at 1550nm wavelength. From compositional analysis revealed the increased N/O ratio would increase refractive index and extinction coefficient, meanwhile the more Si-H and N-H bonds would increase extinction coefficient Microstructure analysis indicated silicon-oxynitride had amorphous structure with some voids might reduce the refractive index and reliability.

The paper presented a new thermally expanded core(TEC) lensed fiber using a standard single-mode fiber(SMF), which was fabricated with a lens at fiber tip using mechanical polishing after expanding the core diameter of a single-mode fiber into about 20μm. This TEC lensed fiber shows that it has the working distance of 60μm and high coupling efficiency (>75%).

In order to reduce the computation time, a new approach for designing computer-generated holograms is proposed. In this new method, we utilize artificial neural network to initiate the genetic algorithm so that the high computation cost of genetic algorithm for synthesizing holograms is significantly reduced while the high diffraction efficiency and uniformity are still ensured. Designed binary phase holograms have the diffraction efficiency of 75.8% and uniformity of 5.8%, which are proven in computer simulation and experimentally demonstrated.

We analyze the thermal properties of the DuPont HRF150-38 photopolymer for digital holographic card manufacture. In case of recording after heating, the diffraction efficiency of the hologram is more than 70% at 100°C but is decreased exponentially at temperatures over 100°C. It is observed in the recording before heating that the diffraction efficiency of the hologram fixed by a UV light is increased to approximately 10% at 100°C, but the hologram are erased at temperatures over 120°C.

Two fiberoptic infrared multi-spectral radiometers were constructed for measurements of the temperature and the emissivity of gray bodies whose temperatures were close to room temperature (40-70°C). In one radiometer, the different spectral regions were obtained by using standard bulk interference filters, and in a second radiometer, the different spectral regions were obtained by using hollow glass waveguides (HGWs) as filters. Using these two radiometers, we carried out temperature and emissivity measurements of three gray bodies which had high emissivity (ε=0.97), medium emissivity (ε=0.71) and low emissivity (ε=0.025). We present the results obtained for these gray bodies and discuss the advantages and disadvantages using each of the radiometers.

A novel reconfigurable true-time delay feed for phased-array antennas working from X to Q (8-50GHz) frequency bands is presented. The reconfigurable optical true-time delay feed, employing monolithic integration of polymer waveguide delay lines and polymeric optical switches, has great advantages in providing power efficient, lightweight, and small size features. Optical switch technique provides large delay selections enabling the module to operate in ultra-broad radar bands. Polymer waveguides with optical propagation loss of less than 0.9dB/cm were achieved at 1550nm. 2X2 thermo-optic switchs as fast as 1ms were fabricated with an excess insertion loss of 0.5 dB in the “switching state” and 1.5dB in the “non-switching state”. Reconfigurability of the true-time delay line was demonstrated through accurate time delay measurement.