A Micromachined Thermo-Optic Tunable Laser

The paper presents a thermo-optic tunable laser that makes use of a micromachined etalon to form the external cavity. The wavelength tuning is obtained by the thermo-optic effect of the silicon material. In experiment, a wavelength tuning range of 14 nm is demonstrated by applying a heating current of 18.7 mA to a deep-etched silicon etalon of 206 mum wide. In the dynamic test, this laser measures a tuning speed of 3.2 mus, which is much faster than the typical speed of 1 ms as given by the previous MEMS tunable lasers that rely on the motion of mirrors or gratings. Since this laser is based on a different tuning mechanism of thermo-optic effect and requires no mechanical movement, it possesses many advantages such as fast speed, simple configuration and planar structure, and will broaden the applications of MEMS tunable lasers.