Stacked edge-emitting lasers having multiple active regions coupled together using tunnel junctions. The composition of each of the active regions (quantum wells and/or barriers) differs to provide a controlled different emission wavelength for each junction, when each junction is individually operated at the same fixed temperature. When the device is under operation, a thermal gradient exists across the junctions, and the emission wavelengths of each junction coincide as the different temperature for each junction causes relative wavelength shifts. Thus, the effect of temperature on the emission wavelength of the device is compensated for, producing a narrower linewidth emission.

A vertical cavity surface emitting laser (VCSEL) may include an epitaxial structure that includes a first active layer, a second active layer, and a tunnel junction therebetween. The VCSEL may include a set of contacts that are electrically connected to the epitaxial structure. The set of contacts may include three or more contacts, and the set of contacts may be electrically separated from each other on the VCSEL. At least one contact, of the set of contacts, may be electrically connected to the epitaxial structure at a depth between the first active layer and the second active layer.

A vertical-cavity surface-emitting laser (VCSEL) array may include an n-type substrate layer and an n-type metal on a bottom surface of the n-type substrate layer. The n-type metal may form a common anode for a group of VCSEL. The VCSEL array may include a bottom mirror structure on a top surface of the n-type substrate layer. The bottom mirror structure may include one or more bottom mirror sections and a tunnel junction to reverse a carrier type within the bottom mirror structure. The VCSEL array may include an active region on the bottom mirror structure and an oxidation layer to provide optical and electrical confinement. The VCSEL array may include an n-type top mirror on the active region, a top contact layer over the n-type top mirror, and a top metal on the top contact layer. The top metal may form an isolated cathode for the VCSEL array.

In some implementations, a vertical cavity surface emitting laser (VCSEL) device includes a substrate layer and a first set of epitaxial layers for a bottom-emitting VCSEL disposed on the substrate layer. The first set of epitaxial layers may include a first set of mirrors and at least one first active layer. The VCSEL device may include a second set of epitaxial layers for a top-emitting VCSEL disposed on the first set of epitaxial layers for the bottom-emitting VCSEL. The second set of epitaxial layers may include a second set of mirrors and at least one second active layer. The top-emitting VCSEL and the bottom-emitting VCSEL may be configured to emit light in opposite light emission directions.

A method for using a photon source, which includes a semiconductor structure having a first light emitting diode region, a second region including a quantum dot, a first voltage source, and a second voltage source, is provided. The method includes steps of applying an electric field across said first light emitting diode region to cause light emission by spontaneous emission, wherein the light emitted from said first light emitting diode region is absorbed in said second region and produces carriers to populate said quantum dot; and applying a tuneable electric field across said second region to control the emission energy of said quantum dot, wherein the light emitted from the second region exits said photon source.

An improvement is made to a non-Raman spectroscopy method and apparatus in which a quantum entangled transmission package formed in a quantum well in a laser is directed to a target and in which the apparatus receives emission packages from the target. A control circuit triggers the laser to emit a laser beam. The transmission package is sent via the laser beam by an emission fiber and the emission package is received by a collection fiber. The collection fiber and the transmission fiber may be included in a Raman probe. The collection fiber provides an input to a monochromator comprising a diffraction grating. The diffraction grating is constructed to permit selection of any of a wide range of wavelengths. A spectrometer receives an output from the diffraction grating. The spectrometer output is measured by a photomultiplier to provide an input to the control module. A number of different spectra are selectively generated. Also, the transmission package may be formed with a power level to affect structure of a preselected target.

Provided is an optical semiconductor device including a laminate structural body 20 in which an n-type compound semiconductor layer 21, an active layer 23, and a p-type compound semiconductor layer 22 are laminated in this order. The active layer 23 includes a multiquantum well structure including a tunnel barrier layer 33, and a compositional variation of a well layer 31.sub.2 adjacent to the p-type compound semiconductor layer 22 is greater than a compositional variation of another well layer 31.sub.1. Band gap energy of the well layer 31.sub.2 adjacent to the p-type compound semiconductor layer 22 is smaller than band gap energy of the other well layer 31.sub.1. A thickness of the well layer 31.sub.2 adjacent to the p-type compound semiconductor layer 22 is greater than a thickness of the other well layer 31.sub.1.

A semiconductor laser diode includes a substrate; a lower epitaxial region located on the substrate, wherein the lower epitaxial region includes a lower DBR layer; an active region located on the lower epitaxial region; and an upper epitaxial region located on the substrate, wherein the upper epitaxial region includes a lower DBR layer; wherein the lower DBR layer includes a P-type lower DBR region and the upper DBR layer includes an N-type upper DBR region.

A VCSEL includes a lower Bragg reflection layer, an active layer and an upper Bragg reflection layer. The active layer is located on a side of the lower Bragg reflection layer. The upper Bragg reflection layer is located on a side of the active layer away from the lower Bragg reflection layer. A current limiting layer is disposed inside or outside the active layer, and the current limiting layer has an opening for defining a light-emitting region. An extended cavity layer is disposed at least between the lower Bragg reflection layer and the active layer or between the upper Bragg reflection layer and the active layer, the extended cavity layer includes at least one resonant cavity inside, and the at least one resonant cavity is configured to increase the optical field intensity in the extended cavity layer.

An optoelectronic semiconductor device (1) comprising a semiconductor body (10) having a first region (101), a second region (102) and an active region (103) configured to emit or detect electromagnetic radiation in an emission direction (S) is described herein. The optoelectronic semiconductor device (1) further comprises a first reflector (21) arranged on a first side of the semiconductor body (10) and a second reflector (22) arranged on a second side of the semiconductor body (10), opposite the first side, a first electrode (31) and a second electrode (32), an aperture region (104) and an optical element (40) arranged downstream of the active region (103) in the emission direction (S). The emission direction (S) is oriented parallel to a stacking direction of the semiconductor body (10). The first electrode (31) is arranged on the first region (101) and the second electrode (32) is arranged between the second reflector (22) and the active region (103). Further, a method for operating an optoelectronic semiconductor device (1) is provided.