Abstract: A method is disclosed in which the principle of phase-coupling is used to stabilize the polarization of laser radiation emitted by a plurality of phase-coupled vertical cavity surface emitting laser elements. Due to a suitable coupling strength between adjacent VCSEL elements, the probability of polarization flips of VCSEL devices operated in the single mode region is zero or at least drastically reduced. Moreover, a VCSEL device is disclosed, comprising a polarization adjusting means for controlling the polarization direction of an arrangement of a plurality of phase-coupled VCSEL elements, wherein the polarization direction of each VCSEL element is substantially kept constant.

Abstract: A vertical-surface-emitting laser comprises: a first reflector and a second reflector arranged to define a laser resonator extending along a longitudinal direction and along transverse directions, a laser active region located between the first and second reflectors, a metal layer at the first or second reflectors and patterned to form a radiation emission window, and a phase matching layer arranged within the resonator and having an optical thickness adapted to transversely pattern a reflectivity of the first and/or second reflectors. The VCSEL device may further comprise an aperture formed between the first and second reflectors. The mode selectivity of the VCSEL is substantially determined by a reflectivity difference defined by the transverse dimensions of the radiation emission window. Moreover, one linear polarization state is stabilized by breaking the cylindrical symmetry of the VCSEL.

Abstract: The present invention relates to a semiconductor laser device and a method for fabrication thereof, wherein the semiconductor laser device exhibits an improved mode selectivity.