Forschungsverbund Berlin E.v.

Ferdinand-braun-institut Ggmbh, Leibniz-institut Fur Höchstfrequenztechnik

Osram Opto Semiconductors Gmbh

Hans Wenzel

Paul Crump

Goetz Erbert

Götz Erbert

Andrea Knigge

Markus Weyers

Joerg Fricke

Günther Tränkle

Pietro Della Casa

Andre Maassdorf

Martin Spreemann

Andre Müller

Bernd Sumpf

Jörg Fricke

Martin Zorn

Olaf Brox

Katrin Paschke

Joachim Piprek

Erbert Götz

Heike Christopher

Jan-Philipp Koester

Anissa Zeghuzi

Mohamed Elattar

Steffen Knigge

Christian Dominik Martin

Frank Bugge

Christoph M Schultz

Andre Maaßdorf

Agnieszka Pietrzak

The present invention relates to a diode laser with a current block and, in particular, to a diode laser with a modified 'p-n-p' or “n-p-n” structure as a current block for reducing the tunneling probability. A diode laser according to the invention comprises an active layer and a layered current block formed outside the active layer, wherein the current block is made of a material doped in opposition to its surroundings for a spatially selective current injection of the active layer between an n-substrate and a p-contact; wherein the current block is separated from adjacent layers via an intrinsic outer layer.

Diode laser with current block

The present invention relates to a device for generating laser radiation. An object of the present invention is to indicate a laser diode which simultaneously has a high degree of efficiency and a low degree of far field divergence. The diode laser according to the invention comprises a current barrier (), characterized in that the current barrier () extends along a third axis (X), wherein the current barrier () has at least one opening, and a first width (W) of the opening of the current barrier () along the third axis (X) is smaller than a second width (W) of the metal p-contact () along the third axis (X).

Device for generating laser radiation

The present disclosure relates to a diode laser having reduced beam divergence. Some implementations reduce a beam divergence in the far field by means of a deliberate modulation of the real refractive index of the diode laser. An area of the diode laser (e.g., the injection zone), may be structured with different materials having different refractive indices. In some implementations, the modulation of the refractive index makes it possible to excite a supermode, the field of which has the same phase (in-phase mode) under the contacts. Light, which propagates under the areas of a lower refractive index, obtains a phase shift of &#x3c0; after passing through the index-guiding trenches. Consequently, the in-phase mode is supported and the formation of the out-of-phase mode is prevented. Consequently, the laser field can, in this way, be stabilized even at high powers such that only a central beam lobe remains in the far field.

Diode laser having reduced beam divergence

The inventive waveguide structure comprises a first waveguide region having a constant first width adapted to guide electromagnetic waves mode sustainably along its longitudinal axis; a second waveguide region adapted to guide electromagnetic waves mode sustainably along its longitudinal axis, wherein the longitudinal axis of the first waveguide region and the longitudinal axis of the second waveguide region form a common longitudinal axis of the waveguide structure, wherein a first end face of the first waveguide region and a first end face of the second waveguide region are aligned with each other, the width of the first end face of the second waveguide region corresponding to the first width, and the width of the second waveguide region along its longitudinal axis widens from the first end face to a second end face to a second width greater than the first width.

Waveguide structure and optical system with waveguide structure

It is the object of the present invention to specify a light source with high efficiency and high eye safety at the same time. For this purpose, the active layer (), the first cladding layer (), the first waveguide layer (), the second waveguide layer (), and the second cladding layer () should be designed such that 0.01 &#x3bc;m&#x2266;d&#x2266;1.0 &#x3bc;m and &#x394;n&#x2267;0.04, where dis the sum total of the layer thickness of the first waveguide layer (), the layer thickness of the active layer (), and the layer thickness of the second waveguide layer () and &#x394;n is a maximum of the refractive index difference between the first cladding layer () and the first waveguide layer () and the refractive index difference between the second waveguide layer () and the second cladding layer ().

Laser diode with high efficiency

A diode laser having aluminum-containing layers and a Bragg grating for stabilizing the emission wavelength achieves an improved output/efficiency. The growth process is divided into two steps for introducing the Bragg grating, wherein a continuous aluminum-free layer and an aluminum-free mask layer are continuously deposited after the first growth process such that the aluminum-containing layer is completely covered by the continuous aluminum-free layer. Structuring is performed outside the reactor without unwanted oxidation of the aluminum-containing semiconductor layer. Subsequently, the pre-structured semiconductor surface is further etched inside the reactor and the structuring is impressed into the aluminum-containing layer. In this process, so little oxygen is inserted into the semiconductor crystal of the aluminum-containing layers in the environment of the grating that output and efficiency of a diode laser are not reduced as compared to a diode laser without grating layers that was produced in an epitaxy step.

Diode laser and method for manufacturing a high-efficiency diode laser

A the vertical-cavity surface-emitting laser includes a stripe-shaped active medium () having an emission maximum at a first wavelength (&#x3bb;), wherein a first reflector () is arranged below the stripe-shaped active medium () and a second reflector () is arranged above the stripe-shaped active medium (), with the first reflector () facing the second reflector (), wherein the first reflector () and a second reflector () have a reflectivity maximum in the region of the first wavelength (&#x3bb;), wherein a third reflector () and a fourth reflector () are each arranged on a side above or next to the stripe-shaped active medium (), wherein the third reflector () faces the fourth reflector (), and wherein the third reflector () and the fourth reflector () have a reflectivity maximum in the region of a second wavelength (&#x3bb;), wherein the first wavelength (&#x3bb;) is greater than the second wavelength (&#x3bb;).

Two-cavity surface-emitting laser

A laser diode has a first n-conducting cladding layer, a first n-conducting waveguide layer arranged therein, an active layer is suitable for generating radiation arranged on the first waveguide layer, a second p-conducting waveguide layer, arranged on the active layer, and a second p-conducting cladding layer, arranged on the second waveguide layer the sum of the layer thickness of the first waveguide layer, the layer thickness of the active layer and the layer thickness of the second waveguide layer is greater than 1 &#x3bc;m and the layer thickness of the second waveguide layer is less than 150 nm. The maximum mode intensity of the fundamental mode is in a region outside the active layer, and the difference between the refractive index of the first waveguide layer and the refractive index of the first cladding layer is between 0.04 and 0.01.

High-efficiency diode laser

A diode laser and a laser resonator for a diode laser are provided, which has high lateral beam quality at high power output, requires little adjustment effort and is inexpensive to produce. The laser resonator according to the invention comprises a gain section (GS), a first planar Bragg reflector (DBR) and a second planar Bragg reflector (DBR), wherein the gain section (GS) has a trapezoidal design and the first planar Bragg reflector (DBR) is arranged on a first base side of the trapezoidal gain section (GS) and the second planar Bragg reflector (DBR) is arranged on the opposing base side of the trapezoidal gain section (GS), wherein the width (D) of the first planar Bragg reflector (DBR) differs from the width (D) of the second planar Bragg reflector (DBR).

Diode laser and laser resonator for a diode laser having improved lateral beam quality

A broad area laser, with high efficiency and small far-field divergence, has an active layer, a first contact and a second contact, each having a width larger than 10 &#x3bc;m. An anti-wave guiding layer, which is positioned laterally with respect to the active region, is enclosed between the first and second contacts, wherein a refractive index of the anti-wave guiding layer is larger than a minimum refractive index of cladding layers. A minimum distance between the anti-wave guiding layer and a projection of one of the contacts on the plane of the anti-wave guiding layer is between 0 and 100 &#x3bc;m.

Broad area diode laser with high efficiency and small far-field divergence

A semiconductor laser has an antiresonant waveguide (), which is formed by a layer sequence applied to a substrate (). The layer sequence has outer waveguide regions (), reflection layers (), and a waveguide core () with an active layer (). With this structure, semiconductor lasers with only slight vertical beam divergence and with a large beam cross section can be produced.

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Berlin, Germany

Hans Wenzel