Arroyo Optics, Inc.

Raytheon Company

Other

Victor Leyva

George A Rakuljic

Anthony Stephen Kewitsch

Xian-Li Yeh

Gang Paul Chen

David M Filgas

Robert D Stultz

Matthew J Klotz

Andrew N Daniele

Juan Carlos Sotelo

N Peter Davis

Avishay Eyal

Kevin Knabe

Huey Lu

In one aspect, a frequency agile LADAR (laser detection and ranging) sensor includes a transmitter configured to provide laser pulses towards a target, a receiver configured to receive a reflected signal from the target and control circuitry configured to tune an optical frequency of a first laser pulse of the laser pulses to be different from an optical frequency of a second laser pulse of the laser pulses and tune an optical frequency of the receiver to be different than an optical frequency of a laser pulse most recently transmitted by the transmitter.

Frequency agile LADAR

A servo system includes multiple servo channels being driven by a common error signal. Each channel has a controller that receives an error signal and provides a drive signal to a driver. The servo channels are arranged serially, with a drive signal from one controller forming the error signal for a downstream controller. As a result, the downstream controller does not attempt to correct for phase error directly, but instead attempts to keep the upstream driver at or near its operational midpoint. The servo channels can be arranged in order of decreasing controller bandwidth, from fastest to slowest. In contrast with a parallel configuration, in which servo channels all simultaneously receive a common error signal, the serial configuration can allow each controller to use its full bandwidth, can eliminate crosstalk between servo channels, and can prevent saturation of upstream drive signals.

Serial servo system and method for controlling an optical path length and a repetition frequency of a mode-locked laser

A laser system comprises a pump diode, fiber, relay optics, and a microchip laser crystal. The pump diode produces light at a first wavelength. The fiber receives the light from the pump diode and produces a round, homogeneous light spot at an output of the fiber. The relay optics receives the light from the fiber. The microchip laser crystal receives the light from the relay optics and produces a linearly polarized single frequency output at a second wavelength. The microchip laser crystal includes a first layer and a second layer. The first layer absorbs the light at the first wavelength and emits light at the second wavelength. The second layer receives the light at the second wavelength and either provides a polarization dependent loss at the second wavelength or maintains a polarization of the light at the second wavelength.

Laser system and method for producing a linearly polarized single frequency output using polarized and non-polarized pump diodes

For systems which disperse individual wavelength components of a DWDM beam into an array of converging beams, the individual wavelength signals are modified for blocking, equalization or other purposes by reflective liquid crystal cells. Thus modulated or modified components are then recombined by the system into an output beam, as by reverse passage through the system. Controlled full extinction or linear attenuation may be introduced by converging asymmetrical beams of separate polarization components for each wavelength into superposed relation on zero twist nematic crystal cells which are voltage controlled so as to retard for extinction of greater than 40 dB or to transform the state of polarization to a selected angle for attenuation. Polarization sensitive elements in the return paths of the reflected beams then filter the rejected components.

Liquid crystal modulator and polarization diversity optics for optical communications

Systems and methods for modifying, switching, rearranging or otherwise controlling the individual wavelength components of DWDM optical signals are described, which employ compact refolding and reshaping of these dimensionally patterned beams within a confined volume. The wavelength components of the beam are diffractively dispersed with high diffraction efficiency, and then reversely converged to beam waists incident on different ones of an array of control elements such as liquid crystal cells, MEMs and other spatial light modulators, or fixed distributed patterns. With reflective control elements the wavelength components may be reversely refolded along reciprocal paths with rediffraction, to form a reconstituted and revised DWDM output signal. If the control elements transmit at least one of the wavelength components, a separate, adjacent three dimensional beam refolding path, with rediffraction, is used to feed recombined signals to a separate output. High diffraction efficiency and minimal optical aberrations are achieved by employing a diffraction grating and opposed Mangin mirror system as the principal elements for beam refolding. The approach is useful in systems servicing narrow channel separations, and in a wide variety of applications including channel equalization, interleaving, channel blocking, and channel grouping.

Diffractive fourier optics for optical communications

Optical components, particularly microoptic glass components used in synthesizing birefringence in filter systems based on polarization interferometer techniques, are fabricated using systems and methods which provide accurate frequency periodicity measurements. These measurements are derived from differential delays induced by in-process glass elements between beam components in a polarization interferometer unit and from progressive wavelength scanning across a wavelength band of interest. The consequent sinusoidal output variation has peak to peak spacings which are measured to provide frequency periodicity values from which precise length corrections for the optical elements can be calculated.

System and method for fabricating components of precise optical path length

A fast acting, low insertion loss switch for use in an optical fiber communication system includes a small diameter waist region incorporating a Bragg grating which is precisely tuned by tensioning to be reflective at a selective wavelength band. By a small physical shift of the waist, as by lateral displacement of an attached small magnetic element with a magnetic field, the periodicity of the grating is varied so that the selected wavelength is passed through the waist with virtually no loss. The incremental motion required can be introduced by a variety of devices, selected in accordance with cost, size and response time requirements. Modules having a number of such switches in close juxtaposition offer distinct advantages for wavelength division multiplexed systems.

Low loss wavelength selective optical switch

An optical signal filter for providing a periodic transfer function in transmitting signals within a selected bandwidth, by which passbands are interleavered into groups of separate outputs. The filter employs the transmissivity characteristic of birefringent crystals in conjunction with splitting the input beam into orthogonal and separate components, while compensating for temperature variations by pairing crystals of different types. The transmissivity functions are independent of the polarization of the input beam, and are shaped to flatten transmissivity peaks by the use of cascaded stages of birefringent crystal pairs.

Interleaving optical filter

Precisely tensioned optical fiber devices are held in a temperature compensated package, with a small diameter span of a fiber containing a Bragg grating of a needed periodicity being supported under tension at opposite ends between spaced apart end members whose thermal expansion characteristics differ from that of an underlying base. The direct points of attachment of the ends of the tensioned span are rotationally as well as axially movable, enabling fine tuning of periodicity and twisting to minimize polarization and dispersion effects. This configuration is also useful for unique methods of assembly of the components, and for use during writing the Bragg grating in the small diameter span.

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Pasadena, CA, United States of America

Victor Leyva