MEMS Tunable Littman-Metcalf Diode Laser at 2.2μm for Rapid Broadband Spectroscopy in Aqueous Solutions

We demonstrate a rapidly (3 ms) and widely (222 nm) tunable, compact external cavity GaSb-based diode laser with a MEMS mirror. It delivers from 8 to 24 mW power over the tuning range, showing the side-mode suppression ratio of >50dB and controllable mode-hops of ∼18GHz.