Quasi RT-CW operation of InGaAs/InGaAsP strained quantum well lasers

Lasers with emission wavelength of 1.8–2.1μm offer many important applications to laser spectroscopy, eye-safe medical care and trace chemical detection. Strained InGaAs/InGaAsP structures on InP substrates have been reported as an alternative approach for the development of semiconductor laser diodes in the spectral range 1.8–2.1μm due to the superior InP substrate quality and mature processing technology. In this paper we report the fabrication and performances of InGaAs/InGaAsP/InP strained quantum well lasers grown by gas source molecular beam epitaxy. The diodes show good I–V characteristics, and the typical turn-on voltage at room temperature is around 0.4–0.5V. A threshold current of about 120mA is achieved for a chip with 500μm cavity length and 4.5μm stripe width. The maximum output power with 10% duty cycle is 18mW. The main peak of the laser spectrum is located at 1.84μm.