Lead chalcogenide VECSEL on Si emitting at 5 µm

A mid-infrared vertical external cavity surface emitting laser (VECSEL) on a Si substrate has been realised. It is optically pumped and emits around 5 µm wavelength. Maximum output power of 26 mWp (limited by the 1.5 µm wavelength pump laser) was observed at 100 K operating temperature with 3 µs pulse widths. The active part is just a 1.3 µm-thick PbTe layer.