SEMICONDUCTOR LASER DEVICE AND OPTICAL DISC DRIVE

摘要

The threshold current of a 780-nm band InGaAsP well layer semiconductor laser device is low. The well layer is made of InGaAsP the P composition of which is 0.51 less than 0.55 to prevent spinodal decomposition in growing InGaAsP. The well layer is subject to compressive strain of 0.65% less than 1% and greater than 0.25% to reduce the threshold current. Thus, a 780-nm wavelength band InAsGaP well layer semiconductor laser device is produced in which degradation of the active region (15) is prevented and the threshold current is reduced. Therefore the laser device can operate for a long time even in outputting high power of 100 mW or greater. A tensile strain of -1.2% is introduced into the barrier layer in the active region (15) thereby to compensate the stress due to the compressive strain of the well layer. As a result the reliability during high output is further increased. <IMAGE>