Abstract: A ridge wavegide laser diode, with an inverse mesa structure, resistant to heat and improved in the adhesion of a contact metal to a contact layer, which can be obtained by forming a polyimide spacer in such a way that polyimide remains only at the lower part of the corner of the inverse mesa structure. In the diode, the contact metal is minimally broken off at the opposite sides of the mesa structure.

Abstract: Disclosed is a method of producing an electron-absorption modulator having a reverse mesa structure. In the electron-absorption modulator, a first clad of a first conductivity type, an active layer of the first conductivity type, a second clad layer of a second conductivity type and an ohmic contact layer of the second conductivity type are formed on a semiconductor substrate of the first conductivity type. Then, a predetermined mask pattern is formed on the ohmic contact layer. Afterwards, the ohmic contact layer is etched by using the mask pattern. Then, the second clad layer and the active layer below the ohmic contact layer are etched in the form of the reverse mesa structure to expose the first clad layer. Then, the first clad layer is etched at a predetermined depth in the form of a mesa structure.