Wavelength tunable semiconductor laser for gas detector and gas detector

摘要

PROBLEM TO BE SOLVED: To provide a wavelength variable semiconductor laser for gas detection, emitting laser beam having high modulation characteristics.;SOLUTION: The wavelength variable semiconductor laser 27 for gas detection is provided with an n-type semiconductor substrate 11, an active layer 17 arranged above the n-type semiconductor substrate and generating light, a p-type clad layer 22 arranged above the active layer, and a diffracting grating oscillating selectively only a light having a specific wavelength among lights generated by the active layer. An element length L representing the length of a propagation direction in which the generated light propagates within the active layer is set to 200 to 500 m which is suitable for increasing the quantity of current per unit area and raising a temperature of the active layer. Further, the p-type clad layer 22 includes a low concentration clad layer 19 having a low impurity concentration and a high concentration clad layer 20 having a high impurity concentrations, which are arranged in this order from the active layer side.;COPYRIGHT: (C)2008,JPO&INPIT