Method for making a semiconductor laser diode, and laser diode

Abstract

A method for making a laser diode with a distributed grating reflector (RT) in a planar section of a semiconductor laser with stabilized wavelength includes providing a diode formed by a substrate (S), a first cladding layer (CL) arranged on the substrate (S), an active layer (A) arranged on the first cladding layer (CL) and adapted to emit a radiation, and a second cladding layer (CL) arranged on the active layer (A), said cladding layers (CL, CL) being adapted to form a heterojunction to allow for efficient injection of current into the active layer (A) and optical confinement, and a contact layer. The manufacturing method provides for creating, on a first portion (ZA) of the device, a waveguide (GO) for confinement of the optical radiation and, on the remaining portion (ZP) of the device, two different gratings for light reflection and confinement. The two gratings define two different zones (R, R), wherein the first zone (R) includes a grating of low order and high duty cycle, and is intended for reflection, and the second zone (R) includes a grating of the same order, or a grating of a higher order than the previous one, and low duty cycle, and is mainly intended for light confinement. The waveguide (GO) for confining the optical radiation is implemented through a lithography and a subsequent etching, whereas the grating (RT) requires a high-resolution lithography and a shallow etching starting from a planar zone.