Semiconductor laser device capable of maintaining the operation current low and method of manufacturing the same

Abstract

In this semiconductor laser device, an InGaP etching block layeras an etching selection layer having etching selectivity for an n-type AlInP current block layer, which is a non-optical-absorption layer, is formed on the n-type current block layer. Since this etching block layerprevents the current block layeron both sides of a ridgefrom being etched during manufacture, a contact layercan be prevented from entering gaps between the sides of this ridgeand the current block layer. Therefore, light oscillating in an active layeris taken out from a device end surface without being absorbed in the contact layer. According to this semiconductor laser device, an oscillation threshold current and an operation current can be maintained low, deterioration of differential quantum efficiency can be prevented and reliability can be improved.