Optical signal processor using electro-optic polymer waveguides

Abstract

We have investigated an optical signal processor using electro-optic polymer waveguides at 1.55 µm. As a result of recent polymer development many new optical devices are becoming available such as optical filters, modulators, switches, multiplexers, etc. It would be useful to have a single optical device, which is reconfigurable, to implement all of these optical devices functions. We call such a device an 'Optical Signal Processor', which will play a similar role as digital signal processors in electrical circuits. We have realized such an optical device using optical-delay-line circuits. Since optical-delay-line circuits are based on the multiple interference of coherent light and can be integrated with enough complexity, they have been utilized for purposes of optical processing such as optical filters. However, the guiding waveguides that were used are passive and the only mechanism used to reconfigure their functions has been thermal. This is slow and cannot be used for high speed applications such as optical modulators and optical packet switches. On the other hand, electro-optic polymers have a very high electro-optic coefficient with a good velocity match between the electrical and optical signals which makes them ideal for efficient, high speed, devices. Therefore, we have investigated delay line optical signal processor circuits using the electro-optic polymer waveguides. These structures are complex enough to generate arbitrary functions and fast enough to obtain high data rates. Using these optical signal processors, we have investigated interesting applications including arbitrary waveform generators.

Design of Ring Resonators Using Electro-Optic Polymer Waveguides

“…In next generation we will also couple rings to each other to obtain interesting cascade interference effects. Its optical transfer function, H, which is the complex ratio of input and output electric fields, can be summarized as H ) R c e jτ c ω t / -Re jτω e jφ 1 -tRe jτω e jφ (1) where ω is optical angular frequency, τ (τ c + τ r ) is the round trip time, R (R c R r ) is the round trip loss factor, t is the transmission coefficient of the coupler, τ c and τ r are the transition time in the coupler and in the ring, and R c and R r are the optical loss factor in the coupler and ring, respectively. The optical loss factors represent the electric field attenuation on a linear scale and become unity in lossless waveguides.…”

“…This element we found is the main building block in this new technology and must be carefully configured and modeled. On the basis of this, we have already made first generation filters, real-time delays, arbitrary waveform generators and linearized modulators . We feel that this is just the first step, using the new materials, in a shift from high speed electronic systems to one which is largely photonic.…”

Giant enhancement of the second harmonic generation efficiency in poled multilayered silica glass structures

“…The prospect of using silica glass as a second-order nonlinear medium introduces a conceptually different approach to the design of optical systems. In today's optical chips any nonlinear functionality is implemented externally to the chip requiring labor-intensive packaging, or on the chip but using multi-material systems [7] that introduce additional fabrication steps and integration challenges. The monolithic integration of second-order nonlinear functions directly within silica-based optical chips would virtually eliminate any insertion losses, thermal mismatch problems and integration issues, and would be completely compatible with standard planar lightwave circuit (PLC) technology.…”