Design and fabrication of all-polymer thermo-optic variable optical attenuator with low power consumption

In this paper, an all-polymer thermo-optic variable optical attenuator (VOA) based on Mach–Zehnder interferometer (MZI) waveguide structure was designed and fabricated on PMMA substrate. To improve the performance of the VOA device, the air trench structure was employed. The improved device presents a low power consumption of 2.8 mW and a high optical attenuation of −40.2 dB. The variation of attenuation was ±2.45 dB within the wavelength ranging from 1530 nm to 1610 nm. Under 1550 nm operating wavelength, the insertion loss of the VOA was measured to be 9.3 dB, and the response time was about 600.0 μs.