70results about How to "Reduce back reflection" patented technology

An EAMR disk drive includes a media, a laser, and a slider coupled with the laser. The laser for provides energy. The slider has an air-bearing surface, a laser input side, an EAMR transducer and an antireflective coating (ARC) layer occupying a portion of the laser input side. The ARC layer is configured to reduce back reflections of the energy. The EAMR transducer includes a write pole, a waveguide optically coupled with the laser and at least one coil. The waveguide has a waveguide input. A portion of the ARC layer resides between the laser and the waveguide input. A method aligns the laser to the ARC layer, and then aligns the laser to the waveguide input. The laser may then be coupled to the slider.

A single-channel, expanded beam connector having a front and rear orientation and comprising: (a) a housing; (b) an outer sleeve at least partially contained by the housing; (c) a first inner sleeve disposed at least partially in the outer sleeve; (d) a ferrule disposed at least partially in the first inner sleeve; (e) a lens disposed at least partially in the first inner sleeve in front of the ferrule, wherein the lens and the ferrule have about the same outside first diameter which is just slightly less than that of the inside diameter of the first inner sleeve such that the ferrule and the lens are held in optical alignment in the first inner sleeve, and wherein the distal end of the outer sleeve extends beyond the inner sleeve to receive a second inner sleeve of a mating structure, the first and second inner sleeves having the same diameter which is just slightly less than the inside diameter of the outer sleeve such that the first and inner sleeves are aligned within the outer sleeve.

Devices to enhance the reliability of optical networks and to reduce the cost of repair are disclosed in this invention. In particular, compact and inexpensive fiber optic union adapters with built-in protective isolation prevent the transfer of damage from one connectorized fiber optic cable to another. The fiber optic union includes a split sleeve with an interior channel and a fiber stub centrally located within the interior channel. The fiber stub makes direct optical contact with the cable endfaces to enable efficient optical transmission between interconnected cables while providing a low loss, low back reflection adiabatic transition between the waveguide cores of the two cables.

A fiber-optic bundle based optical coherence tomography (OCT) probe method is demonstrated in a multimode optical fiber bundle based OCT system. The system can achieve a lateral resolution of 12 μm and an axial resolution of 10 μm using a super-luminescent diode source. This imaging approach eliminates any moving parts in the probe and has a primary advantage for use in extremely compact and safe OCT endoscopes to image internal organs and great potential to be combined with confocal endoscopic microscopy.

The present invention deals with optical systems for providing short laser pulses. An object of the invention is to provide an optical system providing compact and cost-effective short laser-pulses using fibers with anomalous dispersion and high non-linear thresholds. The object is achieved by a short pulse optical system for generating or processing short laser-pulses, said optical system comprises an optical fiber in the form of a photonic crystal fiber arranged to provide guidance of light in the core region due to the photonic bandgap effect (PBG), where light propagates in a hollow or solid core surrounded by a Silica cladding comprising a substantially periodic distribution of micro-structural elements, and where the refractive index of the core is lower than the effective refractive index of the cladding. The invention may be useful in applications such as laser-based micromachining, thin-film formation, laser cleaning, in medicine and biology.

An article of polarized eyewear has a lens with a first substrate lens material transparent to visible light and a pattern of elongated structures formed from at least a second material having a complex index of refraction that is deposited onto a curved surface of the first substrate lens material. The pitch between adjacent elongated structures is less than 300 nm and the width of each elongated structure is less than 90% of the pitch.

A single-aperture, multi-axial transceiver is provided that is particularly useful in a LIDAR system for detecting low velocities at increased ranges. The system is particularly useful in systems that are required to measure very low velocities and very short distances as well as to provide an operating range of hundreds of meters. The transceiver uses closely spaced waveguides placed near the focal point of a single objective 8 to form input and detector apertures. Preferably the input and detector apertures are spaced from each other by less than about 80 μm. In an embodiment using light with a wavelength of 1550 nm, the spacing is preferably about 30 μm.

An integrated circuit includes an optical source (such as a laser) with a lens, which is disposed on an isolator. This isolator is disposed on a semiconductor layer in a silicon-on-insulator (SOI) platform that includes an optical coupler and an optical waveguide. During operation, the optical source generates an optical signal that propagates toward the isolator so that the lens focuses the optical signal. Furthermore, the isolator reduces or eliminates back reflection of the optical signal toward the optical source, and the optical coupler couples the optical signal into the optical waveguide.

Devices to enhance the reliability of optical networks and to reduce the cost of repair are disclosed in this invention. In particular, compact and inexpensive fiber optic union adapters with built-in protective isolation prevent the transfer of damage from one connectorized fiber optic cable to another. The fiber optic union includes a split sleeve with an interior channel and a fiber stub centrally located within the interior channel. The fiber stub makes direct optical contact with the cable endfaces to enable efficient optical transmission between interconnected cables while providing a low loss, low back reflection adiabatic transition between the waveguide cores of the two cables.

An inorganic, dielectric grid polarizer includes an optical stack with a diffraction grating and an inorganic, dielectric grid polarizer. The inorganic, dielectric grid polarizer includes a stack of film layers with an array of parallel ribs in accordance with PGP<lambda / 2 where PGP is the period of the ribs and lambda is the wavelength of the light. The diffraction grating includes an array of elongated parallel dielectric ribs in accordance with PDG>lambda / 2 where PDG is the period of the ribs.

Provided is a spliced-on connector system which includes a connector body, an incoming fiber which is spliced to the connector body, a splice sleeve which covers a splice point at which the incoming fiber is spliced to the connector body, and an extender tube which covers the splice sleeve. Also provided is a method of producing the spliced-on connector system; a holder including a depression which holds a connector body in a position in which the connector body is spliced to an incoming fiber, the holder being disposed inside a splicer which splices the connector body to the incoming fiber; and a splicer including a tube heater which heat-shrinks a splice sleeve over a splice point at which a connector body is spliced to an incoming fiber, the tube heater accommodating the connector holder which holds the connector body.

A polarization device includes an optical stack with a diffraction grating and a wire grid polarizer with one disposed over the other. The wire grid polarizer includes an array of elongated, parallel conductive wires in accordance with PWGP<λ / 2 where PWGP is the period of the wires and λ is the wavelength of the light. The diffraction grating includes an array of elongated parallel dielectric ribs in accordance with PDG>λ / 2 where PDG is the period of the ribs.

An article of polarized eyewear has a lens, with a first substrate lens material transparent to visible light and a pattern of elongated structures formed from at least a second material having a complex index of refraction, wherein the second material is deposited directly onto a curved surface of the first substrate lens material. A pitch between adjacent elongated structures is less than 300 nm and a width of each elongated structure is less than 90% of the pitch. A photochromic material is deposited onto the polarized eyewear.

An inorganic, dielectric grid polarizer includes an optical stack with a diffraction grating and an inorganic, dielectric grid polarizer. The inorganic, dielectric grid polarizer includes a stack of film layers with an array of parallel ribs in accordance with PGP<λ / 2 where PGP is the period of the ribs and λ is the wavelength of the light. The diffraction grating includes an array of elongated parallel dielectric ribs in accordance with PDG>λ / 2 where PDG is the period of the ribs.

An optical subassembly for low-feedback coupling of light from a light source into an optical waveguide such as an optical fiber is described. The optical subassembly has an aspherical lens with surface sag having a rotationally symmetrical sag component without having a cone sag component, and a rotationally asymmetrical helical component for reducing coupling of light reflected from the optical fiber tip back into the laser aperture by causing a significant portion of the reflected light to encircle the laser aperture. The lens shape and the height of the helix are selected so that tight focusing onto the fiber tip is preserved, while the optical feedback is reduced.

A sensing fibre for use in a distributed temperature sensing system comprises an optical fibre to be deployed in a measurement region in which a temperature measurement is to be made, which incorporates a reflective element, such as a join between portions of fibre, and a coiled fibre portion positioned adjacent a distal side of the reflective element, the coiled fibre portion contributing substantially nothing to the spatial extent of the optical fibre when deployed. In use, the effect of any forward propagating light incident on the reflective element that is returned for detection by the system, and which saturates the detector, can be eliminated by removing the part of the detected signal that corresponds to the coiled portion, after which the detector will have recovered. The remaining parts of the signal can be used to derive the distributed temperature profile since these parts represent the whole extent of the sensing fibre owing to the lack of spatial extent of the coil. Coils can be provided on both sides of the reflective element for double-ended temperature sensing techniques.

An expanded-beam connector comprising a sleeve for holding at least one fiber and one lens body, the sleeve having an interior surface having a certain geometry, a fiber having a fiber end face, and a lens body, the lens body being formed with a first face and a second face, the first and second faces being substantially planar, the first face having an interface point for optically coupling with the fiber end face, the second face having a convex surface, the interface point and the convex surface being optically coupled through the lens body, the lens body having an outer periphery at least a portion of which has the certain geometry such that the lens body is held in a precise radial position relative to the sleeve when disposed in the sleeve.

We have seen that some waveguides exhibit variable and increasing back reflection of single wavelength illumination over time, limiting their effectiveness and reliability. We have developed approaches to improve the transmission of these waveguides. We have found that by modulating the illumination wavelength over a small wavelength range we can reduce or eliminate this back reflection from the waveguide. In addition, we describe the writing and erasing of gratings within SiON waveguides by forming standing waves. Methods, systems, instruments, and devices are described that provide improved transmission of light through such waveguides.

The present disclosure provides systems and methods for collecting and converting solar energy into electrical energy. The present invention includes solar collectors that concentrate solar energy and mechanisms for transporting and transferring the concentrated solar energy directly into closed cycle thermodynamic engines without heating the outside surface of the engines. Additionally, the present invention includes multiple thermodynamic engines and mechanisms to direct solar energy into each of the thermodynamic engines to increase overall system efficiency by maximizing the use of collected solar energy. Advantageously, the delivery system of the present invention avoids heating an outside surface of the engine as is done in conventional designs, provides a closed design to protect the collectors, and maximizes efficiency through multiple engines.

A semiconductor distributed Bragg reflector laser configured for single longitudinal mode operation, having an optical waveguide comprising an optical gain section, a first reflector being a first distributed Bragg reflector (DBR) section comprising a grating configured to produce a reflection spectrum having one or more first reflective peaks, and a second reflector, wherein the first DBR section is configured to compensate for thermal chirp that is induced inhomogeneously along the length of the DBR section, in use.

A small Faraday rotator is placed in the inner space of a receptacle and a holder. Because the plane of polarization is rotated, even when backreflection light returns to a laser diode, the lasing state does not become unstable. Being placed in the inner space and fixed there, the Faraday rotator can be small and therefore does not increase the part cost notably. The assembly cost does not increase, because it is not required to tightly press-fit a member into a narrow hole.

A compact variable optical attenuator having optical-tap functionality is described comprising a planar waveguide attenuator, a lens, and a photodetector. Input and output waveguides are located close to the optical axis of the lens, which reduces optical aberrations and insertion loss. The waveguide attenuator works by light absorption with virtually no scattered light present, which improves fidelity of measurements of the tapped optical power by the photodetector. The entire tap-attenuator assembly is packaged into a small form pluggable (SFP) package having two optical connectors.

An apparatus and method for coupling and decoupling optical leads while preventing twists or kinks in the optical leas as well as back reflections with the apparatus including an a rotatable optical coupler and a non-rotatable optical coupler.

A low-cost approach is provided for forming a low splice loss, low back reflection loss and mechanically robust angle-fusion splice between a standard silica fiber and a low-temperature non-silica glass fiber. This is accomplished by angle cleaving the silica fiber, square cleaving the non-silica fiber and then asymmetrically heating the fibers to form an angle fusion splice. A matched angle at the end of the non-silica fiber is generated in situ during the splicing process. The tip of the angle-cleaved silica fiber may be polished flat back to the edge of the core to reduce the range of motion of the non-silica fiber during splicing thereby further reducing splice loss and enhancing the mechanical strength of the joint.

An optical coupling system and method are provided for coupling light from a light source into an optical fiber that reduce back reflection of light into the light source and provide controlled launch conditions that improve forward optical coupling. The optical coupling system comprises at least one flat surface having perturbations formed therein over at least a portion of the flat surface that intersects an optical pathway. The perturbations have a lateral width and a height that are preselected to increase forward optical coupling efficiency and to decrease back reflection of the light beam from the optical fiber end face into the light source. The perturbations improve forward optical coupling by creating a complex light beam shape that is preselected to better match a spatial and angular distribution of a plurality of light modes of the optical fiber.

A technique is described for terminating an optical fiber with low backreflection. At a selected end of the optical fiber segment, an endface is formed at a selected angle relative to the fiber axis. A suitable material is deposited onto the angled endface to form an angled reflective surface. The angled reflective surface is configured such that light propagating along the waveguide to the selected end of the optical fiber segment is reflected back into the optical fiber segment at an angle that prevents coupling of the reflected light into the fiber core. The reflected light is dissipated along the length of the fiber segment.