Preparation of helical biphenyl polyurethane and its low power consumption thermo-optic switch

Abstract

Azo chromophore molecule (NDPD) and helical biphenyl polyurethane (HBPU) were prepared. The chemical structures of NDPD and HBPU were characterized by FTIR and UV–vis spectroscopy. The measurements of refractive index, thermo-optic coefficient (dn/dT), transmission loss, refractive index dispersions and Sellmeyer coefficients of HBPU were measured using ATR technique, CCD digital imaging devices and Sellmeyer equation. The results showed that HBPU would be useful for the design of high performance digital optical switch. The prepared HBPU was utilized as core material to propose a Y-branch thermo-optic switch, which was based on thermo-optic effect of HBPU at the infrared communication wavelength of 1.55μm. With branching angle of 0.143° and the finite difference beam propagation method (FD-BPM), the polymeric thermo-optic switch was simulated. The simulation results indicated that the device has a low switching power of 1.68mW and a switching response time of 7.0ms.