Abstract: A chip-scale scanning lidar includes a two dimensional (2D) scanning micromirror for a transmit beam and a 2D scanning micromirror for a receive beam, a laser diode and a photodetector, a first waveguide and first grating outcoupler coupled to a front facet of the laser diode, a second waveguide and a second grating outcoupler coupled to a rear facet of the laser diode on a substrate. A first fixed micromirror, a second micromirror, a third micromirror, and a focusing component are in a dielectric layer bonded to the substrate over the laser diode and photodetector. The photodetector is optically coupled to the second fixed micromirror and the third fixed micromirror for coherent detection.

Abstract: Systems and methods for dual-mode optical sensing are provided. One system includes a focal-plane array (FPA) imaging detector configured to detect light of a first wavelength range and an illuminated-spot locating detector (ISLD) including an array of light-detecting elements configured to detect light of a second wavelength range, wherein the ISLD has a transparency to light of the first wavelength range. The system further includes a wavelength-selective optical diffuser configured to diffuse light of the second wavelength range, wherein the shortest wavelength of the first range is larger than the longest wavelength of the second range, the ISLD is positioned such that the light to be detected by the FPA imaging detector first passes through the ISLD, and the FPA imaging detector, the ISLD and the wavelength-selective diffuser share a common optical axis.

Abstract: Optical angle of arrival sensors and methods for determining an angle of arrival of incident light are provided, wherein one sensor includes a focusing lens and an array of lateral-effect position sensing detector (LEPSD) elements. The focusing lens is configured to focus light on the array, wherein each of the LEPSD elements includes an absorber region that absorbs light of a first wavelength range that is focused on the LEPSD elements. Each of the LEPSD elements further includes at least one lateral current conducting layer that has a relatively low sheet resistance.

Abstract: Optical angle of arrival sensors and methods for determining an angle of arrival of incident light are provided, wherein one sensor includes a focusing lens and an array of lateral-effect position sensing detector (LEPSD) elements. The focusing lens is configured to focus light on the array, wherein each of the LEPSD elements includes an absorber region that absorbs light of a first wavelength range that is focused on the LEPSD elements. Each of the LEPSD elements further includes at least one lateral current conducting layer that has a relatively low sheet resistance.

Abstract: A method and apparatus for measurement of individual phases of beams from a beam steering laser array relative to a reference laser beam. The disclosed method and apparatus is based on the use of a partially reflecting ellipsoidal reflector or dual paraboloidal reflector having two focal areas to make an image of the laser array located in one of the focal areas appear at the other focal area. Illumination of this image with a phase modulated beam from a reference laser coherent with the laser array allows the application of dithering techniques to measure individual phases of beams from array. Any laser beam in the array or a separate laser coherent with the laser array can be used as a reference beam. In addition, the partially reflecting ellipsoidal reflector or dual paraboloidal reflector can provide protection for the beam steering laser array from environmental impacts or damage.

Abstract: A device is disclosed. The device contains a first electro-optical waveguide comprising at least one first grating, a second electro-optical waveguide comprising at least one second grating, a plurality of electrodes disposed adjacent to the first grating and configured to impose an electric field through the first electro-optical waveguide to modify spectra of the first grating, a fiber amplifier configured to propagate a laser radiation between the first electro-optical waveguide and the second electro-optical waveguide, and at least two circulators associated with the fiber amplifier and the first electro-optical waveguide and the second electro-optical waveguide and configured to provide unidirectional propagation of the laser radiation along the fiber amplifier.

Abstract: A beamsplitter for splitting the light of an incident beam into four separate beams. The beamsplitter includes a pair of gratings each disposed preferably normal to the incident beam and having grating vectors preferably orthogonal to one another. The pair of gratings may be formed on opposite sides of a common substrate. A method of splitting an incident, collimated beam of light of a given wavelength into four separate collimated beams each disposed at angles of elevation ?d from an axis of the collimated beam of light and of azimuth ?d in a plane orthogonal to the axis of the collimated beam of light.

Abstract: A device is disclosed. The device contains a first electro-optical waveguide comprising at least one first grating, a second electro-optical waveguide comprising at least one second grating, a plurality of electrodes disposed adjacent to the first grating and configured to impose an electric field through the first electro-optical waveguide to modify spectra of the first grating, a fiber amplifier configured to propagate a laser radiation between the first electro-optical waveguide and the second electro-optical waveguide, and at least two circulators associated with the fiber amplifier and the first electro-optical waveguide and the second electro-optical waveguide and configured to provide unidirectional propagation of the laser radiation along the fiber amplifier.

Abstract: An input analog signal is applied to electrodes bracketing electro-optically responsive waveguides being driven by a continuous wave or pulsed laser. The waveguides have reflection elements installed with transmission spectra sized, located and designed to transmit the laser light to photodetectors. The transmission of the laser light depends on the shift in transmission spectra caused by the applied analog voltage. The reflection element transmits laser light according to a digital encoding design. The second embodiment describes a device and method for converting high frequency analog signals greater than approximately 10 GHz into digital signals. The high frequency quantizer relies on reflectors reflecting the laser light as a high frequency RF pulse propagates along electrodes bracketing the electro-optically responsive material in the opposite direction of the laser light.

Abstract: A system and method for producing a Bragg grating. A system and a method for apodization of gratings. The system and method for producing a grating include splitting a beam and reflecting one split beam an odd number of times and the other an even number of times before the two are allowed to interfere within a photosensitive target. When the original beam is scanned in predetermined directions, the split beams scan the target while interfering within the target. The original beam is scanned such that an intersection point of the reflected split beams moves along a bisector of the two split beams. In the system and method for apodizing, scanning of the interfering beams along a length of the target may be controlled to yield a substantially uniform average refractive index for the apodized grating that is being recorded in the photosensitive target medium.

Abstract: A system for measuring a laser-induced damage threshold in an optical fiber may include a lens to direct a first laser beam through a core of the optical fiber. The system may also include an optical arrangement to direct a second laser beam through an exterior surface of the optical fiber and into the core of the optical fiber at a preselected location of the optical fiber to provide a predetermined power density at the preselected location, wherein the optical arrangement causes the second laser beam to be directed into the optical fiber substantially completely around a perimeter of the optical fiber to provide the predetermined power density.

Abstract: In one of the embodiments, a dark channel array is provided which includes gain channels, each configured to emit an output beam from an output surface and to have a light wave propagating therethrough. It further includes a dark channel configured to emit an output beam from the output surface of the dark channel array and to have a light wave propagating in the dark channel, such that output beams from the plurality of gain channels are coherently coupled in phase with each other. The dark channel array is configured such that the dark channel captures a portion of the output beam from at least two of the plurality of gain channels by radiant coupling.

Abstract: A method of amplitude electro-optic modulation. The method includes transmitting a narrowband laser light into an electro-optically active waveguide in a first direction. The electro-optically active waveguide has a grating for reflecting the narrowband laser light. The method also includes applying an electric signal to the electro-optically active waveguide and modifying the reflection of the grating in a wavelength region of the narrowband laser light by application of the electric signal.

Abstract: A method and system for spectral suppression of a noise in a communication signal. The method includes transmitting a communication signal through a plurality of rejection filters to create a plurality of spectral holes over a spectrum of the communication signal. The communication signal with an acquired noise is received. Noise intensities of the acquired noise at the plurality of spectral holes are measured, and the acquired noise over the spectrum of the communication signal is calculated. The acquired noise is subtracted from the communication signal with the acquired noise.

Abstract: A system for measuring a laser-induced damage threshold in an optical fiber may include a lens to direct a first laser beam through a core of the optical fiber. The system may also include an optical arrangement to direct a second laser beam through an exterior surface of the optical fiber and into the core of the optical fiber at a preselected location of the optical fiber to provide a predetermined power density at the preselected location, wherein the optical arrangement causes the second laser beam to be directed into the optical fiber substantially completely around a perimeter of the optical fiber to provide the predetermined power density.

Abstract: An outcoupler having a wavelength selective, angle sensitive element or Bragg grating and an arrangement for maintaining the element in a predetermined orientation relative to an incident beam of electromagnetic energy. The Bragg grating may be reflective or transmissive. The inventive outcoupler may be used to implement a phase conjugate master oscillator power amplifier with an oscillator; a resonator in operational alignment with the oscillator; and an outcoupler in alignment with the oscillator. In the best mode, second and third Bragg gratings are included within the oscillator and the resonator, respectively.

Abstract: In one embodiment, a dark channel array is provided which includes gain channels, each gain channel being configured to emit an output beam, and which includes a dark channel configured to cause output beams from the gain channels to be coherently couple in phase with each other.

Abstract: An apparatus and method for pumping optical fibers. An optical element is disposed for directing pump energy into the inner cladding of a dual clad optical fiber, where the optical element has a refractive index greater than the refractive index of the inner cladding. A gradient refractive index structure is disposed between the optical element and the inner cladding to provide for a smooth transition from the refractive index of the optical element to the refractive index of the inner cladding.

Abstract: A system and method for recording a reflection Bragg Grating in a photosensitive target. A photosensitive target is located between transmissive members on three sides. Beams incident on one of the transmissive members pass through the other two members before creating an interference within the photosensitive target. Either two transmissive members are used and the second member limits angular mobility of the first, or three members are used and the third member limits angular mobility of the other two. The target is coupled to the transmissive members through a transmissive liquid that has a refractive index similar to the refractive index of the target. Accordingly, angular deviations in the location of the target from the intended location or in the shape of the target only negligibly impact the interference pattern of the beams in the photosensitive target.

Abstract: A method and apparatus for spatial mode selection of planar waveguide and thin slab lasers in the laser's large cross section size direction. The planar laser has a small cross section size direction orthogonal to a major axis thereof and a large cross section size direction orthogonal to the small cross section size direction and to the major axis. A planar reflector is disposed at one end of the planar laser, the planar reflector having a reflecting surface which is arranged orthogonally to the major axis and parallel to both the small and large cross section size directions of the laser. A Bragg grating is disposed in the optical track of the laser, the Bragg grating having a grating vector which is arranged in the plane normal to said small cross section size direction and at the angle between 0° and 90° to said large cross section size direction for suppression of higher order optical modes in said large cross section size direction.