In this paper, we report the design, synthesis, and optical properties of novel negative-type fluorinated polycarbonate photoresists (FPC-PRs) and their use in thermo-optic switches. The novel polymer films are readily fabricated by spin coating on a silicon wafer followed by irradiation with UV light and post-baking at 110 °C. These films exhibit low roughness, good thermal stability (Td, up to 292 °C), high transparency (up to 97.8% at 400 nm) and high refractive indices (RI, 1.583–1.512 at 1550 nm). Channel optical waveguide and MZI thermo-optic waveguide switch arrays were fabricated based on the direct UV-written technique using the FPC-PR 2. The propagation loss of the channel waveguide was only 0.17 dB cm−1 at 1550 nm. The rise and fall times of the device with an applied 500 Hz square-wave voltage were 837 μs and 381.8 μs, respectively. The applied electric power as the switching power was about 35 mW, and the extinction ratio was measured to be about 14.0 dB.
The azo benzothiazole polyurethane–urea (ABPUU) was synthesized from chromophore molecule 4-[(6-nitrobenzothiazole-2-yl)diazenyl]phenyl-1,3-diamine NBDPD, polyether polyol (NJ-210) and isophorone diisocyanate (IPDI). The structure, thermal property , mechanical property and physical property were characterized and investigated. The refractive index ( n ) and thermo-optic coefficient (d n /d T ) of ABPUU was determined at different temperature and wavelength (532 nm, 650 nm and 850 nm) using attenuated total reflection (ATR) technique. Using the CCD digital imaging devices, transmission loss of ABPUU was measured. A 1 × 2 Y-branched and 2 × 2 Mach–Zehnder interferometer (MZI) switch with two rib waveguides , dual driving electrodes and two critical 3-dB couplers polymeric thermo-optic switches based on thermo-optic effect of prepared ABPUU were designed and simulation. The power consumption of the Y-branched switch is less than 0.84 mW. The Y-branched and MZI switching rising and falling times obtained are 0.8 ms and 0.2 ms, respectively.
In this study, a metal-cladding directly defined active waveguide technique is proposed. Optical waveguide amplifiers and thermo-optic (TO) waveguide switches based on erbium-containing polymer are designed and fabricated using this technique. The Er organic complexes containing polymeric reactivity groups are synthesized and investigated by free radical copolymerization. Optical characteristics and thermal stabilities of the active polymer are analyzed. Relative optical gain of the amplifier at 1530 nm is obtained as 3.6 dB. The rise and fall response time of the TO switch applied by 300 Hz square-wave voltage is measured as 511.7 μs and 341.5 μs, respectively. The power-time product is 12.5 mW ms and the extinction ratio is about 20 dB. The technique is very suitable for realizing large-scale optoelectronic integrated circuits.