Optical signal processor using electro-optic polymer waveguides.

摘要

We have investigated an optical signal processor using electro-optic polymer waveguides operating at a wavelength of 1.55 mum. Due to recent development of optical fiber communications, many useful optical devices have become available to process optical signals such as optical filters, modulators, switches, multiplexers, etc. It would be useful to have a single optical device, which is reconfigurable or programmable to implement all of these functions. If it is general enough to perform all of these functions, we can call such a device an 'optical signal processor', which plays a similar role to digital signal processors in electrical circuits.; We have realized such an optical device in a planar lightwave circuit, which has been intensively investigated over the last few decades. Since the planar lightwave circuit is based on the temporal and multiple interference of coherent light and can be integrated with significant complexity, it has been implimented for various purposes of optical processing such as optical filters. However, the guiding optical waveguides in planar lightwave circuits are mostly passive and the only viable mechanism to tune or configure the circuits functionality is the thermal effect, which is slow and cannot be used for high speed applications such as optical modulators or optical packet switches. On the other hand, electro-optic polymer has a very high electro-optic coefficient and a good velocity match between electrical and optical signal, thus, permitting the creation of high speed optical devices with high efficiency. Therefore, we have implemented an optical signal processor in a planar lightwave circuit using electro-optic polymer waveguides. As a result, the structure is complex enough to generate arbitrary and complex functions and fast enough to obtain high data rates. Furthermore, we focus on its implementation at the optical wavelength of 1.55 mum, which is currently used for optical fiber communications.; In this dissertation, we discuss the principle of operation of an optical signal processor, its design and fabrication issues using electro-optic polymers, and its experimental operation including several example applications, such as an arbitrary waveform generator, linearized modulator, true-time delay element, pulse code generator, and discrete-time signal processor.