A miniature tunable coupled-cavity laser constructed by micromachining technology

This letter presents a miniature tunable coupled-cavity laser by integrating a Fabry-Perot chip, a gain chip and a deep-etched parabolic mirror using micromachining technology. The mirror is to actively adjust the gap between chips, enabling the optimal mode selection. Single-mode operation with a tuning range of 16.55 nm and a side-mode-suppression ratio of >25.1 dB is demonstrated. The device overcomes phase mismatching and instability problems encountered in conventional fixed-gap coupled-cavity lasers.