|dc.description.abstract||Electro-optic (EO) polymer materials have become a promising option for
high-performance integrated optics due to their high nonlinearity, small velocity
mismatch for traveling wave devices, and flexible monolithic integrated capability on
any interested substrates. Based on waveguides fabricated with EO polymers, our
research objectives were (1) to design and fabricate amplifiers, switches, and
modulators and (2) to investigate the possibility of integrating these devices into a
By co-doping rare-earth ions and EO chromophores into photolime gel, a
well-known backbone for holographic materials, we present here a dual-functional
planar waveguide demonstrating the capability of amplification and modulation.
Complete device-fabrication processes, including wafer preparing, polymer
coating and curing, adhesion enhancing of film interfaces, waveguide RIE etching,
electrode patterning and plating, wafer dicing, waveguide polishing, and wire
bonding, have been investigated in depth. All these techniques can be applied to make
not only electro-optic polymeric devices, but thermal-optical polymeric devices as
well. Straight channel array, Y-coupler array, and X-junction have been demonstrated
successfully, all made from polyimides.
With a thermal-setting EO polymer PU-FTC, both corona poling and contact
poling were investigated. A novel domain-inversion poling technique was developed.
We demonstrated an electro-optic modulator based on a 1x2 Y-branch directional
waveguide coupler. The symmetric geometry of this coupler provides the modulator
with the unique characteristics of an intrinsic 3dB operating point and two
complementary output ends. The design, fabrication, and testing of the modulator are
discussed in the dissertation.
A highly linearized Y-coupler modulator is presented lastly. The high linearity
is achieved by suppressing its IMD3 with the ∆β−inversion method. The operation
principle of the device is analyzed here. Substantial suppression was achieved for a
∆β−inverted modulator in a wide dynamic range up to 70% optical modulation depth.
An IMD3 suppression of 47.29dB was observed for this modulator, as opposed to a