| Patent application number | Description | Published |
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| 20090237662 | REAL-TIME, HYBRID AMPLITUDE-TIME DIVISION POLARIMETRIC IMAGING CAMERA - This disclosure relates to a real-time, hybrid amplitude-time division polarimetric imaging camera used to derive and calculate Stokes parameters of input light. | 09-24-2009 |
| 20100078543 | COMPACT HIGH-SPEED THIN MICROMACHINED MEMBRANE DEFORMABLE MIRROR - Provided is a compact, high-speed deformable mirror for use with an adaptive optic. The mirror or wavefront correction device corrects and/or compensates for wavefront aberrations present in a wavefront received by the optics. The mirror includes a deformable membrane which may be made of a semiconductive, metallic or insulating material. Positioned in close proximity to a front surface of the membrane is a transparent conductor, which may be covered by a window having an anti-reflective coating. A plurality of electrostatic actuators is located in close proximity to a back surface of the membrane, the conductor and actuators separated by a gap of approximately 10 μm. In operation, a bias voltage is applied to the transparent conductor and an actuator voltage is applied to the plurality of actuators. The resultant voltage differential across the membrane defines the amount of membrane deformation, which in turn compensates for distortions in a subsequently reflected wavefront. | 04-01-2010 |
| 20100315567 | LIQUID CRYSTAL BASED BROADBAND FILTER FOR FAST POLARIZATION IMAGING - A liquid crystal based broadband filter and imaging system for analyzing the polarization state of radiation. The filter includes four elements: a quarter wave plate; a 45° polarization rotator; a 90° polarization rotator; and a fixed polarizer. The first three of these elements are electronically switchable, allowing the user to select from any of the six possible polarization states. The switchable elements use multiple liquid crystal cells made from dual-frequency materials. A dual-frequency signal is used to activate and deactivate the various elements to achieve the desired state configuration. The dual-frequency signal drives the liquid crystal cells in and out of states, improving the overall switching time of the filter. The configuration of the liquid crystal cells within each of the filter allows broadband operation over most of the visible, infrared and ultraviolet spectra. The filter cycles through six configurations corresponding to the six polarization states of the incident radiation. Thus, the polarization state of the radiation can be completely characterized using the four Stokes parameters. Information related to the intensity and polarization of the radiation can be stored, displayed and analyzed. | 12-16-2010 |
| 20110001896 | TWO-STAGE DRIVE WAVEFORM FOR SWITCHING A DUAL FREQUENCY LIQUID CRYSTAL (DFLC) AT LARGE TILT ANGLES - A two-stage drive waveform switches a DFLC from a high tilt state such as above the LC's linear region or near the ‘saturated’ or ‘field-driven homeotropic’ state of the LC to a low tilt state quickly and without scattering. A relaxation voltage is applied to delay the onset of the high amplitude high frequency kick voltage when switching from a high tilt state to a low tilt state. The relaxation voltage allows the molecules to ‘relax’ in accordance with their own elasticity towards their low tilt state in the direction of the average azimuth angle of the low tilt state. Once the tilt angle has relaxed sufficiently, the kick voltage is applied to drive the molecules quickly to the low tilt state. Most unexpectedly, optimal switching time and the desired molecular response is achieved by delaying the onset of the large kick voltage via application of the relaxation voltage. The relaxation voltage may constitute a lower amplitude holding voltage, a small or zero DC voltage or a smooth windowing of the kick voltage. Whether to apply the relaxation voltage at all and how to apply the relaxation voltage for optimal switching are suitably controlled as a function of the high tilt state. The DFLC is suitably switched from the low-to-high tilt state in the conventional manner without application of a relaxation voltage. | 01-06-2011 |
| 20110079703 | OBJECT TRACKING SYSTEM - An optical tracking system comprises an array of point source emitters that output respective optical emissions, and a plurality of angle of arrival sensors. Each sensor comprises one or more optical elements and a focal plane array (FPA), with the optical elements arranged to resolve the optical emissions into one or more linear patterns on the FPA. A processing system in communication with the sensors establishes the orientation and position of each of the optical emitters using the linear patterns. A headgear tracking system employs point source emitters on a piece of headgear, with front and rear arrays of angle of arrival sensors located in an aircraft cockpit; a processing system in communication with the sensor arrays establishes an orientation and position for each of the optical emitters on the headgear. | 04-07-2011 |
| Patent application number | Description | Published |
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| 20080277570 | HIGH PRECISION COMPACT ROTATION ANGLE ABSOLUTE ENCODER - An angle absolute encoder comprises a code rod encoded with code marks configured in segments, such that each successive segment has an increasing number of code marks, arranged at an angle to the rotation axis depending on the number of code marks in each segment. The angle of the code mark is determined by the number of code marks in the respective segment, the width of the segment parallel to the rotation axis of the code rod and the radius of the code rod. The angular resolution increases according to the number of code marks in each segment. Light is reflected from or transmitted through the code marks and detected by a light detector to determine absolute angle position. | 11-13-2008 |
| 20090168137 | BROAD SPECTRAL RANGE POLARIZATION ROTATOR - A switchable apochromatic polarization rotator is provided. A first fixed waveplate has a first principal axis fixed in a first orientation. A second fixed waveplate has a second principal axis fixed in a second orientation. First and second switchable waveplates have principal axes oriented such that broad spectral range electromagnetic radiation transmitted through all of the waveplates has a first rotated polarization, wherein, in response to one or more control signals applied to the switchable waveplates, the principal axes of the switchable waveplates rotate such that the electromagnetic radiation transmitted through all of the waveplates has a second rotated polarization. The switchable waveplates utilize ferroelectric liquid crystal material, nematic liquid crystal material, or be mechanically rotated to adjust for orientation of their principal axes. Utilizing waveplates as described may be used to tune for a desired spectral range and/or compensate for temperature dependencies. | 07-02-2009 |
| 20090285583 | SNR ENHANCEMENT IN MODULATING RETROREFLECTOR OPTICAL COMMUNICATION LINKS - An optical communication system may include a light transmission unit transmitting a light beam having a first polarization, a quarter waveplate to receive the light beam and to modify the light beam to have a second polarization, and a retroreflector to receive the light beam from the quarter waveplate and reflect the light beam to the quarter waveplate, which modifies the light beam to have a third polarization. The optical communication system may also include a half waveplate to modify the first polarization such that the first polarization is about 90 degrees rotated compared to the third polarization, and a polarizer to pass the light beam having the third polarization and to block most of the light beam having the first polarization. | 11-19-2009 |
