Blue Sky Research

The United States of America As Represented by the Department of Energy

Fizeau Electro-optic Systems, LLC

Other

University of California

The United States of America As Represented by the United States

Soquel Technology, Inc.

James J Snyder

Stephen L Kwiatkowski

Thomas M Baer

Wai-Hon Lee

Donald D Varner

Rolin J Gebelein

James Parsons

Patrick Reichert

Stephen L Kwiatowski

Ross Johnston

A method and system for controlling the wavelength of light emitted by a tunable laser. The system includes a wavelength tuner that provides information of a desired wavelength; a coupler for tapping a portion of the light from the tunable laser; and an apparatus for measuring the actual wavelength of the light. The apparatus takes the portion of the light as an input signal and splits the input signal into two beams that are directed through two paths of different optical lengths. Then, the two beams are interfered with each other in order to form a fringe pattern at an observation plane, where the fringe pattern is detected and analyzed to determine the wavelength of the light. A processor compares the difference between the desired and determined wavelengths, and sends a tuning signal to the tunable laser forming a feedback control of the tunable laser.

Method and apparatus for feedback control of tunable laser wavelength

A method and apparatus for measuring the wavelength of an input light beam whereby the input light beam is split into two light beams which are directed through two paths of different optical length. The light beams are interfered with each other in order to form a fringe pattern at an observation plane, which fringe pattern is detected and analyzed to thereby determine the wavelength of the input light beam.

Method and apparatus for determining the wavelength of an input light beam

A single channel M&times;N optic switch is provided in accordance with the present invention to steer light radiating from any one fiber in an input bundle into any selected fiber in an output bundle. Precision beam-steering optics is implemented using a Risley prism pair controlled by a small computer. In order to efficiently couple light between two single-mode optical fibers a low-aberration lens approximately collimates the light from the source fiber before it is passed through the Risley prisms in order to minimize the aberrations introduced by the prisms as they collectively deflect the beam through some precise angle. A second low-aberration objective lens is used to refocus the light at the core of a selected output fiber. The focusing lens transforms the angular deflection of the beam into a change in the position of the focused spot in the focal plane of the lens. In order to switch the light beam from one fiber in the output bundle to another, the Risley prisms are individually rotated about the optical axis to predetemined orientations so as to deflect the collimated light at the exact angle necessary to direct the focused spot to the core of a selected output fiber.

Single channel M x N optical fiber switch

Electro-optical device characterized by having been formed into an individual unit with an integral optical element, and method to form the device. An optical element, for instance a length of cylindrical microlens, is aligned with a diode strip having a plurality of diodes, for instance laser diodes, and attached to the lens. Subsequent to this attachment, the composite structure consisting of the diode strip having attached to it the lens is sectioned into individual diodes, each of which has a integral lens attached thereto.

Electro-optical device with integral optical element

A read/write arm for use in an optical memory system. The read/write arm of the present invention has reflective surfaces for directing an optical beam from the arm rotation axis on to an optical disk. The arm features a lightweight lens mounted at one end of the arm for focusing a light beam onto an optical disk. The focal distance of the light beam may be adjusted using piezoelectric actuators mounted on the read/write arm for precisely deflecting the arm. The light beam may be further adjusted through use of a relay lens interposed between a collimating lens and the object lens. This arrangement is advantageously optimized through the use of feedback loops.

Optical data storage technology

Laser diode/cylindrical microlens assembly including a crossed-pair of passively aligned cylindrical microlenses attached to a substrate on which is mounted a laser diode chip. The microlenses are mounted in an 'aplanatic' configuration with their flat surfaces facing the emitting facet of the diode, which arrangement provides for passive alignment and possible automated mounting, but requires no additional lenses for astigmatism correction. The crossed pair of lenses can collimate or focus the laser diode beam, for example focusing into a single mode fiber.

Laser diode assembly including a carrier-mounted crossed pair of

Multiple element laser diode assembly incorporating a cylindrical microlens and at least one of an astigmatism correcting element and a collimating element. The use of a single purpose cylindrical microlens, for instance for circularizing a beam of laser light output from said diode, in operative combination with at least one additional optical element for correcting astigmatism and for collimating the beam enables the passive mounting of the several optical elements of the assembly without an active alignment step. The cylindrical microlens may incorporate as single powered surface, as may the astigmatism correction element. Alternatively, the astigmatism correction element may comprise a tilted optical plate. The collimating lens may be a spherical lens.

Multiple element laser diode assembly incorporating a cylindrical

Method for manufacturing cylindrical microlenses having exceptional optical properties, and the lenses manufactured according to the process. According to the present invention, a method is provided for fabricating cylindrical microlenses, the method comprising the steps of forming a glass preform by means of grinding at least one face thereof in the direction transverse to longitudinal axis of the lens, the preform having the shape of a cylindrical lens, and drawing the glass preform to reduce its cross-sectional dimensions while retaining its cross-sectional shape, thereby providing a cylindrical microlens with a high numerical aperture or other desirable characteristics. The drawing step may be facilitated by means of the application of heat to the preform. Further, the preform may be roughly formed to a shape intermediate to its finished form by casting, sintering, extruding, or other glass forming methodology.

Process for manufacturing cylindrical microlenses

A helmet-mounted wireless frequency-modulated infrared beam-actuated auxiliary brakelight system capable of reliable operation in all ranges of ambient light while permitting the rider to turn his head from side to side over a large angle approaching 180 degrees or more. The system comprises a frequency-modulated infrared transmitter, in operative combination with a switch for detecting brake system actuation, and a helmet module, including a frequency-modulated infrared receiver and decoder in operative combination with a stop light. Brake system initiation results in switch actuation which causes the transmitter to emit a beam of frequency-modulated infrared energy towards the helmet module. When the beam is received at the helmet module, it is captured using a lens in operative combination with a novel lightpipe which ensures reception over a 180 degree angle. The infrared energy is then transmitted through a solar filter which further discriminates between solar infrared energy and the infrared beam from the transmitter, before being received at an electro-optical circuit. This circuit decodes the frequency-modulated infrared energy and activates the auxiliary brake lamp.

Motorcycle safety helmet system

This invention relates to a simple, compact, and robust, cylindrical microlens external cavity for laser diode frequency control. The microlens system makes possible a tunable laser diode that utilizes an orthogonal pair of collimating microlenses to form a short external cavity for longitudinal mode and frequency control. The resulting system generates a circular, collimated beam of single frequency, tunable laser radiation. A cylindrical microlens collimator has a powered surface that semi-collimates (i.e., collimates in one axis only) the light from a laser diode. This powered surface is placed so as to be the surface closest to the laser facet. A second lens surface opposite the powered surface, is located in the semi-collimated beam is planar. The second surface of the lens is flat and has a reflective coating. Hence, it provides feedback that is refocused (in one axis) onto the laser aperture. This leads to efficient light coupling back into the laser even if the reflectivity of the second surface is relatively low, and allows the use of lasers with only a single optical output. In another embodiment, a second microlens is used to circularize the beam from the first microlens and the pair of microlenses is mounted onto a translator so as provide frequency tuning of the laser diode.

Cylindrical microlens external cavity for laser diode frequency control

Disclosed is a lens assembly having a first cylindrical microlens having a first microlens longitudinal axis. A flat sheet of material having a hole therein is attached to the microlens, with the microlens traversing the hole. The microlens is oriented with the first microlens longitudinal axis being parallel to the flat sheet, such that the microlens can be illuminated through the hole. In a second embodiment, a second microlens is attached on the opposite side of the sheet and is oriented at an angle relative to the first microlens.

Microlens assemblies and couplers

A new cylindrical minilens and a new lens system for collimating and circularizing the output beam from a laser diode are provided which can be mounted outside the can of a laser diode. The system is made up of two lens elements. The first lens element is a collimating lens which is located to receive the output beam from the laser diode. The collimating lens is typically a standard small lens used in the art for collimating the output beam on a first axis, such that the output beam when it leaves the collimating lens has a desired amount of collimation and has a desired dimension on a second axis that is orthogonal to the first axis. The second lens element is a cylindrical minilens of new design which is located to receive the output beam from the collimating lens, with the cylindrical minilens configured for changing the size of the output beam such that the output beam has a first desired dimension on the first axis and a desired amount of collimation of the output beam on the second axis, so that the output beam is collimated to a desired amount on each axis and has a desired ellipticity.

Monolithic cylindrical optic

A parallel plate lateral shearing interferometer allows the shearing plate to oscillate through a small angle periodically causing the interference fringe pattern to translate on a display surface providing an indication of the direction of adjustment required to collimate a beam. At the point of exact collimation the interference pattern changes abrubtly to a blinking pattern of dark and light. In one embodiment the shearing plate is oscillated by a new kind of electronic translator that functions by thermal expansion and contraction, and in another embodiment the shearing plate moves as a pendulum. An alternative embodiment of the translator is also provided for non-oscillatory precision translations.

Dynamic lateral shearing interferometer

A terminator system particularly suited for beams of high intensity electromagnetic radiation such as from a laser includes an enclosure having a hole therein and a black mirror mounted in the enclosure. The black mirror has a specularly reflecting surface opposite the hole and is oriented at an angle such that the beam impinging on the hole would be impinging on the specularly reflecting surface and would not be reflected directly back out the hole. The black mirror is constructed of a material that absorbs energy at the wavelength of the incident beam. In another preferred embodiment, there are a plurality of black mirrors for performing a succession of reflections, so that the beam power is reduced significantly at each reflection.

Growing community of inventors

Soquel, CA, United States of America

James J Snyder