218 results about "Optical limiting" patented technology

An optoelectronic device, comprising an active region and a waveguide structure to provide optical confinement of light emitted from the active region; a pair of facets on opposite ends of the device, having opposite surface polarity; and one of the facets which has been roughened by a crystallographic chemical etching process, wherein the device is a nonpolar or semipolar (Ga,In,Al,B)N based device.

A single or multi-color light emitting diode (LED) with high extraction efficiency is comprised of a substrate, a buffer layer formed on the substrate, one or more patterned layers deposited on top of the buffer layer, and one or more active layers formed on or between the patterned layers, for example by Lateral Epitaxial Overgrowth (LEO), and including one or more light emitting species, such as quantum wells. The patterned layers include a patterned, perforated or pierced mask made of insulating, semiconducting or metallic material, and materials filling holes in the mask. The patterned layer acts as an optical confining layer due to a contrast of a refractive index with the active layer and/or as a buried diffraction grating due to variation of a refractive index between the mask and the material filling the holes in the mask.

A high efficiency, and possibly highly directional, light emitting diode (LED) with an optimized photonic crystal extractor. The LED is comprised of a substrate, a buffer layer grown on the substrate (if needed), an active layer including emitting species, one or more optical confinement layers that tailor the structure of the guided modes in the LED, and one or more diffraction gratings, wherein the diffraction gratings are two-dimensional photonic crystal extractors. The substrate may be removed and metal layers may be deposited on the buffer layer, photonic crystal and active layer, wherein the metal layers may function as a mirror, an electrical contact, and/or an efficient diffraction grating.

Methods, arrays, and systems for the optical analysis of multiple chemical, biological, or biochemical reactions are provided. The invention includes methods for producing arrays of micromirrors on transparent substrates, each micromirror comprising a nanostructure or optical confinement on its top. The arrays are produced by a process in which lateral dimensions of both the nanostructures and micromirrors are defined in a single step, allowing for control of the relative placement of the features on the substrate, minimizing the process-related defects, allowing for improved optical performance and consistency. In some aspects, the invention provides methods of selectively etching large features on a substrate while not concurrently etching small features. In some aspects, the invention provides methods of etching large features on a substrate using hard mask materials.

A structure using integrated optical elements is comprised of a substrate, a buffer layer grown on the substrate, one or more first patterned layers deposited on top of the buffer layer, wherein each of the first patterned layers is comprised of a bottom lateral epitaxial overgrowth (LEO) mask layer and a LEO nitride layer filling holes in the bottom LEO mask layer, one or more active layers formed on the first patterned layers, and one or more second patterned layers deposited on top of the active layer, wherein each of the second patterned layers is comprised of a top LEO mask layer and a LEO nitride layer filling holes in the top LEO mask layer, wherein the top and/or bottom LEO mask layers act as a mirror, optical confinement layer, grating, wavelength selective element, beam shaping element or beam directing element for the active layers.

A structure using integrated optical elements is comprised of a substrate, a buffer layer grown on the substrate, one or more patterned layers formed on the buffer layer and one or more active layers formed on or between the patterned layers, for instance by Lateral Epitaxial Overgrowth (LEO), and including one or more light emitting species. The patterned layer comprises a mask (made of insulating, semiconducting or metallic material) and material filling holes in the mask. The patterned layer, due to a large index difference with the active layer and/or variations of a refractive index between the mask and materials filling holes in the mask, acts as an optical confinement layer, a mirror, a diffraction grating, a wavelength selective element, a beam shaping element or a beam directing element.

A vertical cavity surface emitting laser (VCSEL) includes independently definable current and optical confinement structures that provide unique forms of drive current and transverse mode confinement, respectively. The optical guide may be formed from an upper distributed Bragg reflector (DBR), as an etched mesa structure and/or as an intracavity optical guide. The current guide may include an ion-implanted region within the upper DBR. A dielectric structure is formed over the upper DBR and surrounds the optical guide.

An object of the present invention is to provide a substrate for a thin film photoelectric conversion device, in which its properties are not deteriorated when its surface unevenness is effectively increased, and then provide the thin film photoelectric conversion device having its performance improved by using the substrate.

According to the present invention, by setting the surface area ratio of a transparent electrode layer in the substrate for the thin film photoelectric conversion device to at least 55% and at most 95%, the surface unevenness are effectively increased to increase the optical confinement effect, while deterioration in properties due to sharpening of the surface level variation is suppressed, whereby making it possible to provide a substrate for a thin film photoelectric conversion device, which can enhance output properties of the thin film photoelectric conversion device.

The invention discloses a nitride light-emitting device for improving the light-emitting efficiency by an electron barrier layer. The light-emitting device disclosed by the invention is provided with the electron barrier layer which is doped with aluminum in a non-uniform and non-periodic manner, and has changed Al components. According to the invention, two key problems of improving the light-emitting efficiency are effectively and simultaneously solved, namely a potential barrier of hole tunneling is reduced and the injection efficiency of a hole is improved; and furthermore, parasitic electron inversion layers are prevented from being formed on interfaces of a quantum barrier and the electron barrier layer by a traditional structure. However, the effect on stopping electrons by a multilayer structure is more obvious and two current carriers of the electrons and the hole are distributed in each quantum well of an active layer in a more balanced and uniform way, so as to obtain the more uniform light gain. Therefore, the light-emitting device provided by the invention can effectively overcome a parasitic quantum well phenomenon and has a smaller threshold current. Furthermore, a waveguide structure is provided with a higher optical limiting factor so that a stronger light-emitting strength is obtained; and therefore, the electric performance and the optical performance of a laser device can be simultaneously improved.

The invention discloses a nitride semiconductor laser, which comprises sequentially a GaN substrate, a n-GaN layer, a n-AlGaN/GaN superlattice limiting layer, a lower InxGa1-xN gradual change waveguide layer, an InGaN/GaN multiple quantum well active area, an upper InyGa1-yN gradual change waveguide layer, a p-AlGaN electron barrier layer, a p-AlGaN/GaN superlattice limiting layer and a p-GaN contacting layer from bottom to top. In component content increases gradually from bottom to top in the lower InxGa1-xN gradual change waveguide layer and In component content decreases gradually from bottom to top in the upper InyGa1-yN gradual change waveguide layer. The nitride semiconductor laser can decrease the stress between an upper InGaN waveguide layer and the p-AlGaN electron barrier layer effectively, so that ragged steps can be avoided during cleavage. Simultaneously, the nitride semiconductor laser can strengthen optical limiting factors of the laser so as to improve performance of the laser effectively and acquire significant effect.

Various embodiment comprise silicon-on-insulator waveguide designs that simultaneously achieve both high optical confinement, low-loss, and provide for electrical connections. In certain embodiments, high index contrast waveguides comprise a central elongate waveguide portion and a segmented portion comprising a single thin layer of Silicon-On-Insulator that achieves both high optical confinement and minimal insertion loss. Other devices, such as chemical and biological sensors, and optical elements may also be fabricated.

High performance media suitable for recording with a blue laser is disclosed. The blue-sensitized holographic media provides greater dynamic range and higher sensitivity than previously disclosed blue-sensitized holographic media. These media can be used for diverse applications such as data storage where the articles provide denser data storage and more rapid hologram writing times or for optical waveguides where the articles provide greater optical confinement and more rapid manufacturing times.

A transmitter optical subassembly (104) includes an optical emitter (130) and a fiber receptacle (122) within which an optical fiber (108) is received. An optical limiting element (134) is positioned between the optical emitter (103) and the fiber receptacle (122). When an optical signal is emitted from the optical emitter, the optical signal passes through the optical limiting (134) element before the optical signal reaches the fiber receptacle (122) and is received the optical fiber. The optical limiting element (134) has a property such that if the power of the optical signal entering the optical limiting element (134) exceeds a predetermined limit, the power of the optical signal is optically attenuated so that the power of the optical signal exiting the optical limiting element remains below a predetermined limit.

An intersubband quantum cascade laser structure includes multiple coupled laser stages, wherein each stage has a multilayer structure including an electron injector, an active region with at least one quantum well, and an electron reflector. Electrons injected from the injector into the active region at a high energy level relax to a lower energy level with the emission of a photon at, for example, mid-infrared wavelengths. The reflector reflects electrons at the higher energy level at which they were injected and transmits electrons from the lower energy level after emission of a photon. Multiple layers of semiconductor are formed on each side of the multistage structure to provide conduction across the device and to provide optical confinement of the photons emitted.

Planar index guided vertical cavity surface emitting laser (PIG VCSEL) utilizes index guiding to provide improved optical confinement and proton implantation to improve current confinement. Index guiding is achieved by etching index guide openings (holes or partial ridges) around the optical confinement region and may be adjusted by varying the etched volume of the index guide openings (holes and partial ridges). The top contact surface area is increased in the PIG VCSEL thereby lowering contact and device resistance to improve VCSEL performance further. The PIG VCSEL is a substantially planarized device for ease of manufacture.

A laser diode structure that includes two different insulator layers, one to maintain good optical confinement, typically located at the sides of the laser ridge, and another to improve the heat dissipation properties, typically located on the etched surfaces away from the ridge.

The invention discloses a novel gallium nitride based semiconductor laser epitaxial structure and a preparation method thereof. According to the invention, p-AlGaN with gradually variable Al components is adopted to act as an optical confinement layer, and through the principle of polarization doping, three-dimensional hole gas is realized. According to the invention, the activation efficiency ofan acceptor Mg impurity can be improved, the device voltage can be reduced, and simultaneously the internal loss of a laser can be reduced effectively.

The invention discloses a single-mode high-power high-brightness GaSb-based bragg reflection master oscillator power amplifier (MOPA) integrated semiconductor laser and a manufacturing method thereof. The bragg reflection MOPA integrated semiconductor device comprises a substrate, an epitaxy structure, a gain amplification region, a master oscillator region, a bragg reflection region and optical limiting grooves, wherein the epitaxy structure grows on the substrate and comprises an N-type lower contact layer, an N-type lower limiting layer, a lower waveguide layer, an active region, an upper waveguide region, a P-type upper limiting layer and a P-type upper contact layer from bottom to top; the gain amplification region is located on the front part, namely a light outlet part, of the semiconductor laser, and is in a conical structure which is formed by etching the P-type upper contact layer downwards; the master oscillator region is located at the rear part of the gain amplification region and is in a ridge waveguide structure which is formed by etching the P-type upper limiting layer downwards; the bragg reflection region is located at the rear part of the master oscillator region and is in a periodical bragg grating structure which is formed by etching the P-type upper limiting layer downwards; and the optical limiting grooves are symmetrically distributed in two sides of the ridge waveguide and are obliquely arranged together with the ridge waveguide.

The invention provides an aluminum-free active region 808nm high-power quantum-well laser with asymmetric structure. From the bottom to the top, the structure of the laser sequentially comprises a substrate, a buffer layer, an N-type lower limiting layer, a lower waveguide layer, a quantum-well layer, an upper waveguide layer, a potential barrier limiting layer, a P-type upper limiting layer, a transition layer and an ohmic contact layer, wherein, the upper waveguide layer and the lower waveguide layer are made of aluminum-free material Indium gallium phosphide, the quantum-well layer made of gallium indium arsenide phosphide material, the waveguide layer and the quantum-well layer form the aluminum-free active region, and one layer potential barrier limiting layer which is made of P-type aluminum gallium indium phosphide material and 50nm-150nm thick and has a band gap wider than that of the upper limiting layer is arranged between the upper limiting layer and the upper waveguide layer. The laser of the invention can increase the optical limiting factor of the P-type material region, reduce the optical leakage towards the P-type material region, reduce optical absorption loss of a current carrier at the highly doped area, and improve the work efficiency of the laser; the structure of the invention also improves the limiting effect of the active region on the carrier, reduce the leakage of the carrier and is favorable to the decrease of the threshold current.

The invention discloses a polyimide-based composite film with optical limiting performance and a preparation method and application of the polyimide-based composite film with optical limiting performance. According to the method, condensation polymerization is conducted on diamidogen and dianhydride to synthesize polyamic acid, then optical limiting material is introduced, and the polyimide-based composite film is obtained through heat amidation processing; the optical limiting material comprises organic dyestuff, carbon black, a carbon nano tube, two-dimensional graphene oxide nano-sheet, two-dimensional reduction graphene nano-sheet, a one-dimensional graphene oxide nanobelt, a one-dimensional reduction graphene nanobelt and a zero-dimensional graphene quantum dot. The prepared composite film has good transmission of light, mechanical property and heat stability, meanwhile has the optical limiting performance prior to that of single optical limiting material, and is hopeful to be applied in the field of laser protection.