Abstract: The present invention relates to a surface-emitting laser diode with an active amplifying region (2) which is bounded by two laser mirrors (1, 3), while one or more polarization-selective layers (4) are provided for stabilizing the polarization in a region that is located on that side of at least one of the laser mirrors (1, 3) that is opposite the active amplifying region (2), these layers (4) extending parallel to the respective mirror (1; 3) and having a polarization-dependent refractive index and/or absorption.

Abstract: A luminous unit for an optical gas detector, an optical gas detector including the luminous unit, and a method of recording an absorption spectrum in an optical gas detector include a light source for linearly polarised light radiation and a housing with an exit window. A wavelength of the light radiation radiated from the light source is tunable. The light source is arranged in the housing such that the main emission direction (OA) of the light source encloses an inclination angle (?) of between 10° and 50° with a normal (N) to the main extension plane (HE) of the exit window. The direction of polarisation (P) of the light radiation encloses a rotation angle (?) of between 22.5° and 67.5° with the plane of incidence on the exit window.

Abstract: The present invention includes a vertical-cavity surface-emitting semiconductor laser diode having a resonator with a first distributed Bragg reflector, an active zone which has a p-n junction and is embedded into a semiconductor layer sequence, and a second distributed Bragg reflector. The semiconductor laser diode has an emission wavelength ?, wherein a periodic structure is arranged within the resonator as an optical grating made of semiconductive material and dielectric material, the main plane of extension of which is arranged substantially perpendicularly to the direction of emission of the semiconductor laser diode. The periodic structure is in direct contact with at least one of the semiconductor layers embedding the active zone and with at least one of the two distributed Bragg reflectors.

Abstract: A surface-emitting semiconductor laser includes an active zone, the active zone having a p-n-junction and surrounded by a first n-doped semiconductor layer and at least one p-doped semiconductor layer; a tunnel contact layer on the p-side of the active zone; an n-doped current-carrying layer that covers the tunnel contact layer, the n-doped current-carrying layer comprising a raised portion; and a structured layer having an optical thickness at least equal to the optical thickness of the current-carrying layer in the region of the raised portion, wherein the structured layer is disposed on the current-carrying layer within a maximum distance of 2 ?m from the raised portion.

Abstract: Methods for producing surface-emitting semi-conductor lasers with tunable waveguiding are disclosed. The laser comprises an active zone containing a pn-transition, surrounded by a first n-doped semiconductor layer and at least one p-doped semiconductor layer. In addition to a tunnel junction on the p-side of the active zone, the tunnel junction borders a second n-doped semi-conductor layer with the exception of an area forming an aperture. An n-doped layer is provided between the layer provided for the tunnel junction and the at least one p-doped semiconductor layer. The tunnel junction may be arranged in a maximum or minimum of the vertical intensity distribution of the electric field strength. This enables surface-emitting laser diodes to be produced in high yields with stabilization of the lateral single-mode operation, high performance and wave guiding properties.