Vi Systems Gmbh

Pbc Lasers Gmbh

Connector Optics Limited

Nl Nanosemiconductor Gmbh

Other

Innolume Gmbh

Nsc-nanosemiconductor Gmbh

Technische Universitaet Berlin

Vertically Integrated (vi) Systems Gmbh

Russian Limited Liability Company "connector Optics"

Vitaly Shchukin

Nikolai Ledentsov

Nikolay Ledentsov

James A Lott

Dieter Bimberg

Joerg-Reinhardt Kropp

An in-plane-emitting semiconductor diode laser employs a surface-trapped optical mode existing at a boundary between a distributed Bragg reflector and a homogeneous medium, dielectric or air. The device can operate in both TM-polarized and TE-polarized modes. The mode exhibits an oscillatory decay in the DBR away from the surface and an evanescent decay in the dielectric or in the air. The active region is preferably placed in the top part of the DBR close to the surface. The mode behavior strongly depends on the wavelength of light, upon increase of the wavelength the mode becomes more and more extended into the homogeneous medium, the optical confinement factor of the mode in the active region drops until the surface-trapped mode vanishes. Upon a decrease of the wavelength, the leakage loss of the mode into the substrate increases. Thus, there is an optimum wavelength, at which the laser threshold current density is minimum, and at which the lasing starts. This optimum wavelength is temperature-stabilized, and shifts upon temperature increase at a low rate less than 0.1 nm/K, indicating wavelength-stabilized operation of the device. The approach applies also to semiconductor optical amplifiers or semiconductor gain chips which are also wavelength-stabilized. Reflectivity of the surface-trapped mode from an uncoated facet of the device can be extremely low, also &#x3c;1E&#x2212;4 or even &#x3c;1E&#x2212;5 which is particularly advantageous for amplifiers or gain chips. For diode lasers, a specific intermediate reflective coating can be deposited on the facet to put its reflectivity into a range from 0.5% to 3%, which lies within targeted values for lasers. An optical integrated circuit can employ wavelength-stabilized amplifiers operating in a surface-trapped mode, wherein such devices amplify light propagating along a dielectric waveguide.

Wavelength-stabilized near-field optoelectronic device

An optoelectronic device employs a surface-trapped TM-polarized optical mode existing at a boundary between a distributed Bragg reflector (DBR) and a homogeneous medium, dielectric or air. The device contains a resonant optical cavity surrounded by two DBRs, and an additional DBR section on top supporting the surface-trapped mode. Selective chemical transformation, like selective oxidation, etching or alloy composition intermixing form a central core and a periphery having different vertical profiles of the refractive index. Therefore, the longitudinal VCSEL mode in the core is non-orthogonal to the surface-trapped mode in the periphery, and the two modes can be transformed into each other. Such transformation allows fabrication of a number of optoelectronic devices and systems like a single transverse mode VCSEL, an integrated optical circuit operating as an optical amplifier, an integrated optical circuit combining a VCSEL and a resonant cavity photodetector, etc.

Optoelectronic device based on a surface-trapped optical mode

The invention discloses a semiconductor optoelectronic micro-device comprising at least one cavity and at least one multilayer interference reflector. The device represents a micrometer-scale pillar with an arbitrary shape of the cross section. The device includes a vertical optical cavity, a gain medium and means of injection of nonequilibrium carriers into the gain medium, most preferably, via current injection in a p-n-junction geometry. To allow high electric-to-optic power conversion at least one contact is placed on the sidewalls of the micropillar overlapping with at least one doped section of the device. Means for the current path towards the contacts and for the heat dissipation from the gain medium are provided. Arrays of micro-devices can be fabricated on single wafer or mounted on single carrier. Devices with different cross-section of the micropillar emit light at different wavelengths.

Micropillar optoelectronic device

An oxide-confined vertical cavity surface emitting laser including a distributed Bragg reflector (DBR) wherein the layers of the (DBR) includes a multi-section layer consisting of a first section having a moderately high aluminum composition, an second section which is an insertion having a low aluminum composition, and a third section which is an oxide-confined aperture formed by partial oxidation of a layer having a high aluminum composition (95% and above). A difference in aluminum composition between a high value in the aperture layer and a moderately high value in the first section prevents non-desirable oxidation of the first section from the mesa side while the aperture layer is being oxidized. A low aluminum composition in the second section prevents non-desirable oxidation in the vertical direction of the layer adjacent to the targeted aperture layer.

Reliable high-speed oxide-confined vertical-cavity surface-emitting laser

Optoelectronic device undergoes selective chemical transformation like alloy compositional intermixing forming a non-transformed core region and an adjacent to it periphery where transformation has occurred. Activated by selective implantation or diffusion of impurities like Zinc or Silicon, implantation or diffusion of point defects, or laser annealing, transformation results in a change of the refractive index such that the vertical profile of the refractive index at the periphery is distinct from that in the core. Therefore the optical modes of the core are no longer orthogonal to the modes of the periphery, are optically coupled to them and exhibit lateral leakage losses to the periphery. High order transverse optical modes associated to the same vertical optical mode have higher lateral leakage losses to the periphery than the fundamental transverse optical mode, thus supporting single transverse mode operation of the device. This approach applies to single transverse mode vertical cavity surface emitting lasers, edge-emitting lasers and coherently coupled arrays of such devices.

Optoelectronic device with enhanced lateral leakage of high order transverse optical modes into alloy-intermixed regions and method of making same

Optical beam quality of an optoelectronic device is improved by suppression of high-order transverse optical modes by their resonant interaction with the continuum of modes in the surrounding regions, such continuum being realized by replacement of one or several layers by layers having a lower refractive index. In particular, selective oxidation of GaAlAs-based vertical cavity surface emitting laser results in (Ga)AlO layers surrounding the aperture and having a lower refractive index than the original (Ga)AlAs layers. The continuum of optical modes originates due to the modification of the optical field in the areas surrounding the aperture caused by the low index insertions positioned to result in enhancement of the optical field in their vicinity. High-order lateral optical modes in the aperture region exhibit larger leakage losses than the fundamental lateral optical mode due to the resonant interaction with the continuum of modes outside the aperture, enabling single-mode lasing from a broad aperture vertical cavity surface emitting laser.

Optoelectronic device with resonant suppression of high order optical modes and method of making same

A laser system for generation of three-dimensional (3D) colored images based on laser sources generating light at a plurality of wavelengths including basic color range (red, green and blue) that illuminate a two-dimensional display, at a given color range wherein a plurality of 2D images formed at different depths by image light impinges on a first optical element, with wavelength-sensitive focal length. All images of the given colored range are perceived by the human's eyes as a single 3D image of this color range. 3D images in red, green and blue that are formed at different positions, are fused by a second optical element, with adjustable focal length. As the light is switched between red, green and blue color ranges, the adjustable focal length is adjusted to compensate a change of the focal length of the first element, so the human's eyes see a fully colored 3D image.

Laser system for generation of colored three-dimensional images

A method for fabrication of three-dimensional nanostructures on top of the surface of a first solid state material is disclosed, which includes steps of (i) deposition of a layer of a second solid state material forming a stable layer-like coverage of the surface, (ii) the subsequent deposition of a third solid state material, having a stronger binding energy with the first solid state material than the second solid state material, (iii) wherein the third solid state material replaces the second solid state material forming an interface with the first material and thus reduces the energy of the system, and (iv) where the resulting excess second solid state material forms three-dimensional nanostructures. The structure can be covered with another (fourth) solid state material, which eventually can be the same as the first material or a different one, and the three dimensional nanostructures form capped quantum dots or quantum wires. The deposition steps can be repeated and extended to provide necessary functionality in the resulting device structure.

Three-dimensional semiconductor nanoheterostructure and method of making same

An optoelectronic semiconductor device is disclosed wherein the device is a vertical-cavity surface-emitting laser or a photodiode containing a section, the top part of which is electrically isolated from the rest of the device. The electric isolation can be realized by etching a set of holes and selective oxidation of AlGaAs layer or layers such that the oxide forms a continuous layer or layers everywhere beneath the top surface of this section. Alternatively, a device can be grown epitaxially on a semi-insulating substrate, and a round trench around a section of the device can be etched down to the semi-insulating substrate thus isolating this section electrically from the rest of the device. Then if top contact pads are deposited on top of the electrically isolated section, the pads have a low capacitance, and a pad capacitance below two hundred femto-Farads, and the total capacitance of the device below three hundred femto-Farads can be reached.

Low capacitance optoelectronic device

A light-emitting device epitaxially-grown on a GaAs substrate which contains an active region composed of AlGaAs alloy or of related superlattices of this materials system is disclosed. This active region either includes tensile-strained GaP-rich insertions aimed to increase the forbidden gap of the active region targeting the bright red, orange, yellow, or green spectral ranges, or is confined by regions with GaP-rich insertions aimed to increase the barrier height for electrons in the conduction band preventing the leakage of the nonequilibrium carriers outside of the light-generation region.

Optoelectronic device with a wide bandgap and method of making same

The present invention refers to a method for robust multi-level encoding of optical signals. The method uses a transmitter that transforms electric signals into optical signals and a receiver capable to transform optical signals into electric signals. The transmitter is capable to generate optical pulses having at least two different durations. The amplitudes of the pulses are preferably close to each other. The transmitter is fast, and the receiver is slow such that the response time of the receiver exceeds at least the shortest of the durations of the optical pulses. Then the receiver effectively integrates the optical signal and generates the electric signal having a larger amplitude when the optical signal has a larger duration. Thus, the method converts the modulation in pulse duration into the modulation in signal amplitude. In different embodiments of the present invention, the transmitter can be realized by a light-emitting diode, superluminescent light-emitting diode, or a diode laser. The receiver can be realized by a p-i-n diode, by a resonant cavity photodetector, or by an avalanche photodiode.

Method for encoding and decoding of optical signals

An optoelectronic interconnect which includes optical transmitter and detector having capacitances below 150 femto-Farads each suitable for transmission of optical signals at speeds at and above 20 Gigabit per second at power consumption below 10 milliWatt per Gigabit per second.

Optoelectronic interconnect for high frequency data transmission at low power consumption

A tilted wave semiconductor diode laser containing additional structural elements that improve beam quality is provided. The tilted wave laser includes a narrow active waveguide coupled to a broad passive waveguide, and light generated in the active waveguide leaks to the broad waveguide and propagates in it in the form of a tilted optical wave. The device emits laser light coming out from the broad waveguide in the form of one or two narrow beams. The additional structural elements may include grooves intersecting the narrow waveguide and a stripe that suppress undesired emission from the narrow waveguide; grooves that extend parallel to the stripe that suppress parasitic lateral optical modes; unpumped sections of the stripe that suppress light emission from the narrow waveguide; and facet coatings having distinct reflectance for the light in the narrow and in the broad waveguides thus suppressing emission of light from the narrow waveguide.

Semiconductor optoelectronic device with improved beam quality

Hybrid integration of vertical cavity surface emitting lasers (VCSELs) and/or other optical device components with silicon-based integrated circuits. A multitude of individual VCSELs or optical devices are processed on the surface of a compound semiconductor wafer and then transferred to a silicon-based integrated circuit. A specific sacrificial or removable separation layer is employed between the optical components and the mother semiconductor substrate. The transfer of the optical components to a carrier substrate is followed by the elimination of the sacrificial or separation layer and simultaneous removal of the mother substrate. This is followed by the attachment and interconnection of the optical components to the surface of, or embedded within the upper layers of, an integrated circuit, followed by the release of the components from the carrier substrate. It is possible to place and interconnect VCSELs directly within the physical structure of the integrated circuit, thus greatly reducing the power requirements, the distance of interconnecting lines, and the resultant operational speed. A variation allows the selective placement of groups of physically-connected VCSELs, and the collection and placement of large numbers of fabricated VCSELs onto foreign substrates using a vacuum plating tool.

Method for attaching optical components onto silicon-based integrated circuits

A device contains at least one wavelength-tunable multilayer interference reflector controlled by an applied voltage and at least one cavity. The stopband edge wavelength of the wavelength-tunable multilayer interference reflector is preferably electrooptically tuned using the quantum confined Stark effect in the vicinity of the cavity mode (or a composite cavity mode), resulting in a modulated transmittance of the multilayer interference reflector. A light-emitting medium is preferably introduced in the cavity or in one of the cavities permitting the optoelectronic device to work as an intensity-modulated light-emitting diode or diode laser by applying an injection current. The device preferably contains at least three electric contacts to apply forward or reverse bias and may operate as a vertical cavity surface-emitting light emitter or modulator or as an edge-emitting light emitter or modulator. Using a multilayer interference reflector containing tunable section allows also obtaining a wavelength-tunable laser or a wavelength-tunable resonant cavity photodetector in the case where the optical field profile in the active cavity or cavities is affected by the stopband wavelength shift. Adding additional modulator sections enables applications in semiconductor optical amplifiers, frequency converters or lock-in optical amplifiers.

Growing community of inventors

Berlin, Germany

Vitaly Shchukin