Temperature dependent characteristics of 0.98-μm strained-quantum-well lasers

Semiconductor lasers emitting in the 0.98-μm wavelength regime are promising for pumping optical fiber amplifiers and solid-state lasers. Although the short wavelength lasers are typically observed to have a high characteristic temperature To, their differential efficiencies often decrease rapidly with temperature increase, which can cause serious problems in many applications. In this work, we investigate the physical causes of this temperature dependence experimentally as well as theoretically with buried heterostructure InGa As / InGaAsP / InGaP strained quantum well lasers. Laser bars of various cavity lengths were measured at temperatures between 10°C to 160°C. Testing unbonded laser bars allows us to perform measurements of many lasers with similar conditions. Thus, effects due to unintentional variations from fabrication or cleaving can be eliminated.