Fluorinated photopolymer waveguide thermo-optic switches with loss-compensation function based on erbium-containing cladding structure

Abstract

In this work, a novel polymer thermo-optic switch with loss compensation function is successfully designed and fabricated by direct UV-writing technology. The waveguide core and cladding layer material of the switch are based on the low-loss fluorinated photopolymer and erbium-containing gain copolymer. The absorption loss characteristics and thermal stabilities of the core and cladding materials are studied. The optimal optical field distribution for loss-compensation structures is analyzed by modifying refractive index difference between the core and cladding. The thermo-optic modulation effect of the optical signal transmission for the device is simulated. The insertion loss of the switch device is about 6 dB. The switching rise and fall time are 396.2 μs and 461.2 μs applied by 500 Hz square-wave voltage, respectively. The switching power is 6.5 mW, the extinction ratio of the switch is about 14 dB. The loss-compensation value of the entire chip is obtained as 1.9 dB at 1530 nm wavelength. The flexible loss-compensation multi-functional waveguide switch is appropriate for incorporation in large-scale opti-electronic integrated circuits.

Study of an Integration Platform Based on an Adiabatic Active-Layer Waveguide Connection for InP Photonic Device Integration Mirroring That of Heterogeneous Integration on Silicon

“…To reduce the optical absorption loss and improve the thermal stability of the fibermode coupling gratings, instead of using BCB polymer, highly fluorinated polymer can be used as the cladding material above and below the grating, which is composed of fluorinated bis-phenol-A novolac resin (FSU-8) and fluorinated, epoxy-terminated, lowmolecular-weight bisphenol A polycarbonate (FBPA-PC EP). The fluorinated polymer has low optical absorption loss at the 1550-nm wavelength range due to reduced vibration overtone by replacing the C-H bonds with C-F bonds [17,18]. More importantly, the polymer material, when used for covering the InGaAsP grating teeth, can help to lower the temperature dependence of the grating coupling wavelength, making it athermal.…”