Patent ID: 6078603
Filing Date: 2000-06-20
Classification: H01S

Abstract:
A semiconductor diode laser with a semiconductor body (100) comprising a substrate (1) and a semiconductor layer structure situated thereon with at least a first cladding layer (2) of a first conductivity type, a second cladding layer (4) of a second conductivity type opposed to the first, and an active layer (3) arranged therebetween, and comprising a pn junction which, given a sufficient current strength in the forward direction, is capable of generating coherent electromagnetic radiation in a strip-shaped active region which lies within a resonant cavity and forms part of the active layer (3), the first and the second cladding layer (2, 4) being provided with electrical connection means (7, 8), while the resonant cavity is bounded by end faces (50, 51) which are substantially perpendicular to the active region and of which at least one end face (51) is provided with a coating (20), the generated electromagnetic radiation issuing from the laser in the form of pulses during continuous operation of the laser, characterized in that the coating (20) comprises in that order a first mirror (21), a medium (22) having an optical thickness at least substantially equal to an integer number of times half the wavelength of the generated electromagnetic radiation, and a second mirror (23), said coating (20) comprising exclusively materials having a greater bandgap than that which corresponds to the wavelength of the generated radiation, while the reflectivity values of the mirrors and the deviation of the optical thickness of said medium from an integer number of times half the wavelength of the generated radiation are chosen such that the group velocity dispersion is negative adjacent the wavelength of the generated electromagnetic radiation.