Diode-pumped broadly tunable self-seeded single-frequency Cr:ZnSe laser

We demonstrate a diode-pumped, broadly tunable single-frequency Cr:ZnSe laser. This system utilizes a 5 mm Cr:ZnSe crystal, pumped by laser diodes (LDs) with a central wavelength of 1710 nm. To achieve unidirectional operation, a retro-reflecting device is used to reflect the self-seeded beam back into the resonator. Single-frequency operation is achieved by finely adjusting three birefringent filters (BRFs) in the resonator, and the linewidth is maintained at less than 29 MHz throughout this tuning range. This compact diode-pumped, broadly tunable single-frequency Cr:ZnSe laser has significant potential applications for detecting various gas molecules.