摘要：A nanosecond response waveguide electro-optic （EO） switch based on ultraviolet （UV） sensitive polymers of Norland optical adhesive （NOA73） and Dispersed Red 1 （DR1） doped SU-8 （DR1/SU-8） is designed and fabricated. The absorption properties, refractive indexes, and surface morphologies of NOA73 film are characterized. The single-mode transmission condition is computed by the effective index method, and the percentage of optical field distributed in EO layer is optimized to be 93.78 %. By means of spin-coating, thermal evaporation, photolithography, and inductively coupled plasma etching, a Mach-Zehnder inverted-rib waveguide EO switch with micro-strip line electrode is fabricated on a silicon substrate. Scanning electron microscope characterization proves the physic-chemical compatibility between NOA73 cladding and DR1/SU-8 core material. The optical transmission loss of the fabricated switch is measured to be 2.5 dB/cm. The rise time and fall time of switching are 3.199 ns and 2.559 ns, respectively. These results indicate that the inverted-rib wave- guide based on UV-curable polymers can effectively reduce the optical transmission loss and improve the time response performance of an EO switch.

摘要：A polymer directional coupler （DC） electro-optic switch with push-pull electrodes and rib waveguides is designed based on the conformal transforming method, image method, coupled mode theory, and electro-optic modulation theory. Its structure and principle are described, the design and optimization are performed, and the characteristics are analyzed, including the coupling length, switching voltage, output power, insertion loss, and crosstalk. To realize normal switching function,the fabrication tolerance,wavelength shift, and coupling loss between a single mode fiber （SMF） and the waveguide are discussed. Simulation results show that the coupling length is 3082μm; the push-pull switching voltage is 2.14V;and the insertion loss and crosstalk are less than 1.14 and -30dB,respectively. The proposed analytical technique on waveguides and electrodes is proven to be accurate and computationally efficient when compared with the beam propa- gation method （BPM） and the experimental results.