Study of a Diode-Pumped Semiconductor Disk Laser Based on a CdS/ZnSe/ZnSSe Heterostructure

A heterostructure with resonant-periodic gain, containing eight ZnSe/CdS/ZnSe quantum wells with type-II band offsets is fabricated by metal-organic vapor-phase epitaxy. Based on this structure, a semiconductor disk laser longitudinally pumped by laser diode radiation with a wavelength of 430 nm is implemented. A composite cavity including a microcavity and an external feedback mirror is used. Laser characteristics are studied as functions of the cavity length. In the case of a cavity close to the semiconcentric one, a pulsed power of 57 mW at a wavelength of 521 nm is achieved at a differential efficiency of 1.5% with an angular divergence of ~10°. The radiation divergence decreased to 5 mrad when using a semiconfocal cavity. However, the laser power significantly decreases because of a high lasing threshold. Way for improving the laser characteristics are discussed.