Wavelength Tuning of Double-Cavity Micromachined Filter with Electrical and Thermal Actuations

We demonstrate double-cavity micromachined tunable filters with electrical actuations for both blue and red wavelength tuning. Electrical actuations for both shifts can be achieved by combining electrostatic and electro-thermal actuations below and above the breakdown voltage of p-n junctions in the micromachined cantilevers. The measured tuning range with the actuation is 8 nm for both tuning sides and the micromachined filter with a cantilever length of 80 μm exhibits a switching time of less than 115 μs for both turn-on and turn-off states. We also present the theoretical and measured temperature dependence of fabricated micromachined filters at various cantilever lengths, which experimentally gives us a temperature dependence of 0.14 nm/K for a cantilever length of 100 μm.