6561 results about "Laser diode" patented technology

A light emitting device, such as a light emitting diode or a laser diode. The light emitting device comprises a light emitting semiconductor active region disposed on a substrate. The substrate comprises an optical absorption coefficient below about 100 cm⁻¹ at wavelengths between 700 and 465 nm a GaN single crystal having a dislocation density of less than 10⁴ per cm² and an optical absorption coefficient below about 100 cm⁻¹ at wavelengths between 700 and 465 nm. A method of making such a light emitting device is also provided.

An inventive semiconductor laser diode includes a Group III nitride semiconductor layered structure having a major crystal growth plane defined by a non-polar or semi-polar-plane. The Group III nitride semiconductor layered structure includes: a p-type cladding layer and an n-type cladding layer; an In-containing p-type guide layer and an In-containing n-type guide layer held between the p-type cladding layer and the n-type cladding layer; and an In-containing light emitting layer held between the p-type guide layer and the n-type guide layer.

A high-intensity light source is formed by a micro array of a semiconductor light source such as a LEDs, laser diodes, or VCSEL placed densely on a liquid or gas cooled thermally conductive substrate. The semiconductor devices are typically attached by a joining process to electrically conductive patterns on the substrate, and driven by a microprocessor controlled power supply. An optic element is placed over the micro array to achieve improved directionality, intensity, and/or spectral purity of the output beam. The light module may be used for such processes as, for example, fluorescence, inspection and measurement, photopolymerzation, ionization, sterilization, debris removal, and other photochemical processes.

A laser diode, grown on a miscut nonpolar or semipolar substrate, with lower threshold current density and longer stimulated emission wavelength, compared to conventional laser diode structures, wherein the laser diode's (1) n-type layers are grown in a nitrogen carrier gas, (2) quantum well layers and barrier layers are grown at a slower growth rate as compared to other device layers (enabling growth of the p-type layers at higher temperature), (3) high Al content electron blocking layer enables growth of layers above the active region at a higher temperature, and (4) asymmetric AlGaN SPSLS allowed growth of high Al containing p-AlGaN layers. Various other techniques were used to improve the conductivity of the p-type layers and minimize the contact resistance of the contact layer.

A large area nitride crystal, comprising gallium and nitrogen, with a non-polar or semi-polar large-area face, is disclosed, along with a method for making. The crystal is useful as a substrate for a light emitting diode, a laser diode, a transistor, a photodetector, a solar cell, or for photoelectrochemical water splitting for hydrogen generation.

Radiant energy line source(s) (e.g., laser diode array) and anamorphic relay receiving radiant energy therefrom and directing that energy to a substrate in a relatively uniform line image. The line image is scanned with respect to the substrate for treatment thereof. Good uniformity is provided even when the line source is uneven. Optionally, delimiting aperture(s) located in the anamorphic relay focal plane and a subsequent imaging relay are includeable to permit substrate exposure in strips with boundaries between adjacent strips within scribe lines between circuits. An anamorphic relay focal plane mask with a predetermined pattern can be used to define portions of the substrate to be treated with the substrate and mask scanning motions synchronized with each other. Control of source output, and position/speed of the substrate, with respect to the line image, allows uniform dose and required magnitude over the substrate.

A III-nitride edge-emitting laser diode is formed on a surface of a III-nitride substrate having a semipolar orientation, wherein the III-nitride substrate is cleaved by creating a cleavage line along a direction substantially perpendicular to a nonpolar orientation of the III-nitride substrate, and then applying force along the cleavage line to create one or more cleaved facets of the III-nitride substrate, wherein the cleaved facets have an m-plane or a-plane orientation.

A semiconductor laser device has a semiconductor laser diode structure made of group III nitride semiconductors having major growth surfaces defined by nonpolar planes or semipolar planes. The semiconductor laser diode structure includes a p-type cladding layer and an n-type cladding layer, a p-type guide layer and an n-type guide layer held between the p-type cladding layer and the n-type cladding layer, and an active layer containing In held between the p-type guide layer and the n-type guide layer. The In compositions in the p-type guide layer and the n-type guide layer are increased as approaching the active layer respectively. Each of the p-type guide layer and the n-type guide layer may have a plurality of In_xGa_1-xN layers (0≦x≦1). In this case, the plurality of In_xGa_1-xN layers may be stacked in such order that the In compositions therein are increased as approaching the active layer.

An optical device having a structured active region configured for one or more selected wavelengths of light emissions and formed on an off-cut m-plane gallium and nitrogen containing substrate.

A group III nitride semiconductor light emitting device according to the present invention includes an immediate layer formed of Al_xGa_1-x-yIn_yN (0<x<1, 0<y<1, x+y<1) between an active layer and a cladding layer and an electron blocking layer formed of p-type group III nitride semiconductor having a smaller electron affinity than that of the intermediate layer so as to be in contact with the intermediate layer. The semiconductor light emitting layer may be a laser diode or a LED.

A multi-wavelength laser device includes at least two of a blue laser diode, a red laser diode, and an infrared laser diode, which are arranged in the same direction on the same base. One laser light emission point is arranged behind another in increasing order of wavelengths of the laser diodes.

A low voltage laser device having an active region configured for one or more selected wavelengths of light emissions.

PCT No. PCT/IL96/00006 Sec. 371 Date Jul. 9, 1998 Sec. 102(e) Date Jul. 9, 1998 PCT Filed Jun. 6, 1996 PCT Pub. No. WO96/41566 PCT Pub. Date Dec. 27, 1996There is described a new sensor for optical blood oximetry as well as a method and apparatus in which the new sensor is used. The new sensor includes two point-like light emitters (23,24) positioned in the center of the device in close proximity to each other and at least one and preferably two annular detector terminals (32,39) concentrically surrounding the light emitters. The light sources may, for example, be two laser diodes emitting each monochromatic light within the range of 670 nm to 940 nm. The detector devices are, for example, photodetectors.

A method for fabricating Al_xGa_1-xN-cladding-free nonpolar III-nitride based laser diodes or light emitting diodes. Due to the absence of polarization fields in the nonpolar crystal planes, these nonpolar devices have thick quantum wells that function as an optical waveguide to effectively confine the optical mode to the active region and eliminate the need for Al-containing waveguide cladding layers.

A laser diode device operable at a one or more wavelength ranges. The device has a first waveguide provided on a non-polar or semipolar crystal plane of gallium containing material. In a specific embodiment, the first waveguide has a first gain characteristic and a first direction. In a specific embodiment, the first waveguide has a first end and a second end and a first length defined between the first end and the second end. The device has a second waveguide provided on a non-polar or semipolar crystal plane of gallium containing material. In a specific embodiment, the second waveguide has a second gain characteristic and a second direction. In a specific embodiment, the second waveguide has a first end, a second end, and a second length defined between the first end and the second end. In a specific embodiment, the second waveguide has the first end being coupled to the first end of the first waveguide. The second length is in a different direction from the second length. In a specific embodiment, the device has a cleaved region provided on the second end of the second waveguide, the cleaved region being perpendicular to the second direction of the second waveguide.

The invention provides a monitor for measuring blood pressure and other vital signs from a patient without using a cuff. The monitor features a housing with a first surface that, in turn, supports a first sensor. The first sensor features: i) an optical system with one or more light sources (e.g., LEDs or laser diodes) that generate optical radiation, and a photodetector oriented to collect radiation after it irradiates the patient and in response generate an optical signal; and ii) a first electrode. A second sensor features a second electrode paired with the first electrode that collects an electrical signal from the patient. A microprocessor in electrical communication with the first and second sensor receives the optical and electrical signals and processes them with an algorithm to determine systolic and diastolic blood pressure.

New devices and methods are provided for noninvasive and noncontact real-time measurements of tissue blood velocity. The invention uses a digital imaging device such as a detector array that allows independent intensity measurements at each pixel to capture images of laser speckle patterns on any surfaces, such as tissue surfaces. The laser speckle is generated by illuminating the surface of interest with an expanded beam from a laser source such as a laser diode or a HeNe laser as long as the detector can detect that particular laser radiation. Digitized speckle images are analyzed using new algorithms for tissue optics and blood optics employing multiple scattering analysis and laser Doppler velocimetry analysis. The resultant two-dimensional images can be displayed on a color monitor and superimposed on images of the tissues.

A non-invasive near infrared spectrophotometric monitoring transducer assembly includes a housing member, which is adhered directly on a patient's skin. The housing member contains a prism coupled to a flexible and lightweight single core optical light guide, which provides a means of transferring narrow spectral bandwidth light from multiple distant laser diodes of different wavelengths by use of a multi-fiber optic light combining assembly. Different wavelengths are needed to monitor the level of blood oxygenation in the patient. The assembly also contains a planar light guide mounted on the prism located in the housing member, which light guide contacts the patient's skin when the housing member is adhered to the patient's skin. The light guide controls the spacing between the prism and the patient's skin, and therefore controls the intensity of the area on the patient's skin which is illuminated by the laser light. The housing member contains a photodiode assembly, which detects the infrared light at a second location on the skin to determine light absorption. The photodiode assembly is preferably shielded from ambient electromagnetic interference (EMI) by an optically transparent EMI attenuating window. This rigid window placed over the photodiode also provides a planar interface between the assembly and the skin, improving optical coupling and stability as well as reducing the capacitive coupling between skin and the photodiode resulting in further EMI attenuation. The housing may be associated with a disposable sterile hydrogel coated adhesive envelope, or pad, which when applied to the patient's skin will adhere the housing to the patient's skin. The transducer assembly will thus be reusable, and skin-contacting part of the device, i.e., the envelope or pad can be discarded after a single use. The assembly also includes a laser safety interlock means, which is operable to turn off the laser light output in the event that the assembly accidentally becomes detached from the patient's skin.