Reliant Laser Corp.

Sunshine Medical Instruments, Inc.

Other

K2 Optronics, Inc.

Vladimir Kupershmidt

Michael Terence Black

John Cameron Major

Mikhail Kouchnir

Sabeur Siala

Frans Kusnadi

Robert Petersen

Michael Spitkovsky

Austin Gormley

Allen W L Topping

The present invention relates to an analog transmitter using an external cavity laser (ECL) in which specific characteristics of the ECL are enhanced and exploited to improve 2nd and 3rd order distortion while increasing the threshold for the occurrence of deleterious stimulated Brillouin scattering (SBS). The performance of the ECL shows a substantial reduction in distortion occurring over certain narrow ranges of operating temperatures. Optical, electronic, thermal and/or mechanical methods are described that cause this 'distortion dip' to be moved to, or created at, stable regions of ECL operation, away from mode hops. Methods are also described that allow the distortion dip to be moved to, or created at, ECL operating regions in which sufficiently high chirp occurs, thereby reducing SBS. Transmitters and other devices employing these and related techniques are also described.

Analog transmitter using an external cavity laser (ECL)

An ECLD assembly includes a thermally stabilized substrate, a laser device fixedly mounted in relation to the substrate, and a waveguide with a grating region having a grating formed therein. The waveguide is positioned to receive light emitted by the laser device and is attached to a top surface of the substrate. The ECLD's output wavelength is stabilized by one or more of the following: (1) mounting the waveguide so that its outer surface is less than 60 &#x3bc;m, and preferably less than about 30 &#x3bc;m from the top surface of the substrate; (2) placing a thermal cover (e.g., a generally semi-cylindrical shell or a strip of material formed with a V-groove) in thermal contact with the substrate and overlies at least a portion of the grating region; (3) bonding the waveguide to the substrate at first, second, and third positions where the first position is proximate the laser device, the second position is proximate a first end of the grating region, and the third position is proximate a second end of the grating region.

Wavelength stabilization of an external cavity laser diode (ECLD)

A system for encoding, comparing, and recognizing individuals by analysis of their fingernails employs collimated light having finite bandwidth ( ). The light ( ) is divided into polarized scanning and reference beams ( ) and ( ). The scanning beam scans across a subject's nail bed ( ), and the light ( ) reflected from the birefringent component within the nail bed is compared with the reference beam ( ). As the scanning beam ( ) scans across the subject's nail bed, more or less light reflects from the nail bed ( ), according to the peaks and valleys in the epidermal folds ( ) of the nail bed. The reflected light is analyzed and reduced to binary data as a function of position across the subject's nail bed. These binary data are used to uniquely identify an individual. The data from a scan can be compared with stored data in a pattern recognition algorithm ( ), resulting in a positive or negative identification of an individual.

Automated identification through analysis of optical birefringence within nail beds

A pocket-type apparatus for non-invasive measurement of blood glucose concentration based on producing a polarized-modulated laser beam via an optical phase shifter (32), measuring a phase difference introduced, e.g., by a finger (F) or a ear lobule (E) of a subject, measuring phase difference between a reference signal (SR) and a measurement signal (SM), and processing the obtained data which are then presented as blood glucose concentration. The optical phase shifter (32) comprises a pair of fiber-optic arms (40 and 42). The laser beam is fed to one of the fiber-optic arms (4) then both arms are guided through an input optical coupler (44) which splits the laser beam into a first component, which further propagates through the first optic-fiber arm (40), and a second component, which propagates through second optic-fiber arm (42). An optical phase shifter (48) which is attached to the first fiber-optic arm (40) modulates the first component of the laser beam. Both arms are then guided through an output optical coupler (46) which coherently mixes the light-propagating modes of the fiber-optic arms so that the output of each arm has a complementary coherent mixture of the beam first and second components with an orthogonal direction of polarization. An output of one of the fiber-optic arms is used as a reference optical signal and an output of the other fiber-optic arm is used as a measuring optical signal.

Optical phase modulator for high resolution phase measurements

A method and apparatus for analyzing a sample wherein at least two orthogonally polarized, intensity and phase modulated laser beams with different wavelengths and frequencies of intensity and phase modulation are directed onto the sample, and the signals derived from the laser beams which interact with the sample are synchronously demodulated to determine characteristics of the sample such as index of refraction, absorption coefficient and film thickness. A reference beam can be provided to correct for noise and drift.

Multiple wavelength polarization-modulated ellipsometer with

A method and an apparatus for the analysis of particles contained in a material, such as particles in a fluid or on a surface, such as the surface of a semiconductor, by two orthogonally polarized, intensity and phase modulated laser beams, wherein the detected scattered light is synchronously demodulated. The apparatus comprises a laser source producing a polarized laser beam, a state of polarization modulator, and a photoreceiver for detecting light scattered by particles at an angle to the incident light. A synchronous demodulator, such as a dual channel lock-in amplifier, separates the intensity and phase modulated portions of the scattered signals. A reference unit for detecting a non-scattered light produced by the sample to provide a reference is preferably provided, as well. The size, index of refraction and identity, of the particles, for example, can be determined.

Method and apparatus for detection, analysis and identification of

A method and apparatus for non-invasive measurement of blood glucose concentration based on producing a polarized-modulated laser beam via a polarizing frequency shifter (24), measuring a phase difference introduced, e.g., by a finger (F) or a ear lobule (E) of a subject, measuring phase difference between a reference signal (SR) and a probe signal (SP), and processing the obtained data which are then presented as blood glucose concentration. The apparatus for the above-mentioned measurements comprises an infrared laser source (22), a polarized frequency shifter (24) which produces a polarized-modulated infrared laser beam, a piezoelectric transducer (26) for driving the polarizing frequency shifter (24), and an optical transducer (30) with a glucose measuring head (32). The latter has an optical input for receiving the laser beam and a balanced receiver (62). During measurement, the finger (F) is inserted into the glucose sensing unit (32), and after passing through the finger, the probe optical beam is converted into an electrical signal, compared with the reference electrical signal, and the obtained phase difference is processed by an electronic signal processing unit (34) which presents the results in the form of blood glucose concentration. Embodiments of the apparatus and method based on measurement of circular dichroism caused by the presence of glucose in blood are included.

Method and apparatus for non-invasive phase sensitive measurement of

A mirror-based laser processing system, e.g., for laser welding, provided with manual control of movements of a laser welding spot W on an object O being treated. The system includes a laser source (10) which generates a laser beam capable of treating the object (O), a mirror-based micromanipulator (14) which consists of a concave mirror (18) and a convex mirror (16) facing each other, and a laser beam splitter (20) which is located on the path of the laser beam reflected from concave mirror (18). The object is located in a focusing position of the laser beam reflected from the laser beam splitter (20). The system has a sensor head (32) for controlling the positions and temperature of the welding spot W. The sensor head is provided with a laser unpenetrated protective window (34), a neutral-density filter (36) which attenuates the infrared scattering light reflected from object O being treated, an infrared narrow-band filter 38 which passes only thermal components of the scattered infrared light, and photodetectors (40) and (42), which convert the intensity of the received light into electrical signals which carry information about the spatial temperature distribution in the vicinity of welding spot W.

Mirror-based laser-processing system with temperature and position

A pocket-type apparatus for non-invasive measurement of blood glucose concentration based on producing a polarized-modulated laser beam via an optical phase shifter (32), measuring a phase difference introduced, e.g., by a finger (F) or a ear lobule (E) of a subject, measuring phase difference between a reference signal (SR) and a measurement signal (SM), and processing the obtained data which are then presented as blood glucose concentration. The optical phase shifter (32) comprises a pair of fiber-optic arms (40 and 42). The laser beam is fed to one of the fiber-optic arms (4), then both arms are guided through an input optical coupler (44) which splits the laser beam into a first component, which further propagates through the first optic-fiber arm (40), and a second component, which propagates through second optic-fiber arm (42). An optical phase shifter (48) which is attached to the first fiber-optic arm (40) modulates the first component of the laser beam. Both arms are then guided through an output optical coupler (46) which coherently mixes the light-propagating modes of the fiber-optic arms so that the output of each arm has a complementary coherent mixture of the beam first and second components with an orthogonal direction of polarization. An output of one of the fiber-optic arms is used as a reference optical signal and an output of the other fiber-optic arm is used as a measuring optical signal.

Pocket-type instrument for non-invasive measurement of blood glucose

Liquid crystal sunglasses indicating overexposure to UV-radiation comprising a pair of liquid-crystal lenses (12 and 14) a rim (10), a bridge portion (14) which support the lenses, and a pair of temples (18 and 20) which supported by the rim. The rim (10) supports a pair of solar cells (28 and 30) and a dual-photodetector sensor (26) which can separately measure an incident UV-A radiation and a UV-B radiation and convert these radiations into electric signals. The sunglasses's rim also incorporates a microcontroller (36). The lenses have a laminated structure composed of a color mask (43), an input polarizing plate (44), a liquid crystal cell (50) sandwiched between a pair of voltage-controlled active matrices, and an output polarizing plate (46). Each active matrix consists of a plurality of sets of pixels which control the transmission of light through the respective color cells of a mosaic mask. The microcontroller also incorporates a frequency generator (104) and a memory unit. The memory stores an algorithm for calculating thresholds of UV radiation. When these thresholds are exceeded the lenses give to the wearer a warning signal either changing the color of the lenses or causing blinking.

Liquid-crystal sunglasses indicating overexposure to UV-radiation

A mirror-based laser processing system, e.g., for laser welding, provided with manual control of movements of a laser welding spot W on an object O being treated. The system includes a laser source (10) which generates a laser beam capable of treating the object (O), a mirror-based micromanipulator (14) which consists of a concave mirror (18) and a convex mirror (16) facing each other, and a laser beam splitter (20) which is located on the path of the laser beam reflected from the concave mirror (18). The laser beam splitter (20) has a coating which reflects the laser beam onto the object (O), but is capable of passing visible and infrared light. Movements of the laser-beam splitter are manually controlled from an external terminal, which is made in the form of a joy stick (50). The joy stick is capable of moving the laser welding spot (W) in any direction over the object's surface in the X-Y coordinate system. Adjustment in the Z-axis direction is performed through a zoom system of the mirror-based micromanipulator (14). The infrared light which is generated by the heated area of the object passes through the laser-beam splitter which transmits visible light to the microscopic head for observation of the object and reflects the infrared light. The latter is processed by a processing unit (38) and is converted into visible thermal information presented on a display (46) in the form convenient for manual control of the position of the welding spot W.

Mirror-based laser-processing system with visual tracking and position

An electro-optical system intended for medical use that measures and analyses an individual's cumulative short-wave and long-wave UV-radiation exposure as detected by sensor 10 of the system attached to the individual. Sensor 10 separately registers sequences of UV-A and UV-B signals which are synchronized in time by clock pulses. After a predetermined interval sensor 10 is connected to an analyzer unit 12 that statistically processes the collected data to derive risk factor and generate predictive information. Such information permits the physician to predict individual-specific levels of ultraviolet (UV) radiation potentially harmful to the skin and help protect the individual from skin cancer and similar diseases with solar radiation causation.

Electro-optical system for measuring and analyzing accumulated

A fiber-optic probe for soft-tissue laser surgery such as angioplasty comprising a section of an optical fiber having a beam-inlet end (23) and a beam-outlet end (22) and composed of a beam-propagating core (18) and a cladding (19) a part of which is removed in the form of openings (20, 21) through which a portion of the laser beam leaves the fiber-optic probe and is directed laterally to the longitudinal axis 34 of the fiber to the operation site. The intensity distribution of the outgoing beam can be controlled by selecting a required pattern of distribution of the openings.

Fiber-optic probe for soft-tissue laser surgery

Glasses with multilayered, color-switchable lenses (102) and (104) for blocking harmful radiation include a rim (100) connected to temples (108) and (110). The rim contains a photosensor (116), a color-changing switch (118), a dry-cell power source (120), solar cells (121) and (123), an electronic driver unit (122), and an electronic circuit (124). The color-switchable lenses comprise glass plates (126a), (126b), and (126c), conductive layers (136a), (136c) (142a), and (142b), color polarizers (138a) and (136c), alignment layers (140a), (140c), (146), and (148), a neutral polarizer (144), and liquid-crystal layers (158) and (160). When the photosensor determines that the intensity of incident radiation falls above or below the specified threshold, an amplified signal is sent via the circuit to the electronic driver unit which supplies layers 158 and 160 with voltages which cause the color-switchable lenses to change their spectral transmittance characteristics.

Glasses with color-switchable, multi-layered lenses

A liquid-crystal matrix-type reflection mirror (10) with a localized dazzle light attenuation zone. The mirror has a multilayered structure and consists of a broadband reflective base mirror (12) having maximum reflectivity in the range corresponding to spectral range of halogen lamps of automobile headlights. Deposited on the base mirror are a matrix transparent electrode (14) and a photoconductive layer (20) placed on the matrix transparent electrode. The photoconductive layer (20) and the matrix transparent electrode (14) have a matrix-type structure formed as a pixel array. Each pixel of the matrix transparent electrode (14) is a projection of an overlaid pixel of the photoconductive layer (20). The multilayered structure further includes the following subsequent layers: a rear polarizer (22) which has a predetermined axis of polarization and is placed on the photoconductive layer, a common transparent electrode (36), a liquid crystal (25) sandwiched and sealed between the rear polarizer (22) and the common transparent electrode (36), a front polarizer (42), and an antireflection coating (44). The mirror (10) has a control circuit connected between the common transparent electrode (36) and the matrix transparent electrode. The control circuit applies a control voltage to the liquid crystal in accordance with the incident light. The pixel enabling just the dazzle light zone to be attenuating.

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Pleasanton, CA, United States of America

Vladimir Kupershmidt