Low-loss and broadband 1 × 8 thermo-optic selective switch using bent directional couplers

Low-loss and broadband optical switches are essential components for all optical networks. In this paper, we experimentally demonstrate a 1 × 8 thermo-optic switch that exhibits broadband property with the worst crosstalk of −17.20 dB and the maximum fiber-to-fiber loss of 5.56 dB over the wavelength range from 1500 to 1630 nm. The elementary unit, which is based on 2 × 2 Mach-Zehnder interferometers utilizing bent directional couplers, demonstrates a crosstalk less than −19.08 dB and the extinction ratio larger than 18.92 dB, from 1500 nm to 1630 nm. For 1 × 8 switch, the power consumption of channel switching is lower than 1.204 W. The measured rise (10 %–90 %) and fall (90 %–10 %) time of the switch unit are 1.04 ms and 600 μs, respectively. These favorable performances promise the demonstrated switch potential in all optical network applications.