A thermally tunable GaAlAs-GaAs micromachined optical filter with submillisecond tuning speed

We fabricated a GaAlAs-GaAs thermally tunable vertical-cavity filter with a thermal strain control layer and heating element on a micromachined cantilever structure. We achieved a large negative temperature dependence of -0.79 nm/K for the vertical-cavity filter by loading a GaAs strain control layer. The tuning voltage is as low as 4.9 V for wavelength tuning of 18.1 nm. We examined the dynamic response of the thermally tunable micromachined GaAlAs-GaAs filter, exhibiting both rise time and fall time of below 100 μs.