PURPOSE: To obtain a semiconductor light emitting element having excellent differential gain by providing a quantum well layer and a barrier layer made of AlInAs or AlGaInAsP, setting the thicknesses of the well layers to specific values or less, and setting the integrated value of the thickness of the well layers to a specific range.
CONSTITUTION: A lower clad layer 2 made of an InP layer and a lower light confinement layer 3 made of an AlGaInAs layer are laminated on an InP substrate 1. Further, a strain compensating type multiplex quantum well layer 4 in which twelve quantum well layers 12 made of Ga0.32In0.68As layers each having a thickness of 4.5nm and thirteen barrier layers 13 made of AlGaInAs layers each having a thickness of 8nm are alternately formed is formed. Then, an upper light confinement layer 5 and an upper clad layer 6 are laminated, a region to be an optical path via the mask layer is retained, removed by etching, and a current narrowing structure layer 8 is formed on the region. Thereafter, a negative electrode 9 is formed on the lower surface, a contact layer 7, a Ti-Pt-Au layer are deposited on the upper surface and a positive electrode 10 is formed.
NISHIKATA KAZUAKI
FUKUSHIMA TORU
IRIKAWA MASANORI
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