Semiconductor optical amplifier, the polarization dependence of the compensation method for their preparation and gain

摘要

PROBLEM TO BE SOLVED: To compensate the polarization dependence of the gain caused after mountg the device by selecting two split electrodes divided in a stripe direction for injecting a current into an active layer having a sectional structure and crystal compsn. continuously varying in the stripe direction, thereby varying the length of current injected regions. SOLUTION: The optical amplifier has an active layer 107 is composed of three regions in stripe direction: one stationary compsn. region 112 having an active layer in which the in-plane strain of a crystal and the sectional shape are const. along the stripe, and a single structured electrode 102 for injecting a current into the active layer to obain a gain. The remaining is two compsn. transmission regions 111 formed on both sides of the region 112, each having an active layer having a crystal-in-plane strain and sectional shape continuously varying along the stripe and two or more electrode 102 split in the stripe direction for injecting a current into the active layer to vary the current-injected region length to adjust the polarization dependence of the gain.