Abstract: Drive-embedded dither pickoff embodiments for a dither motor of a ring laser gyroscope are disclosed. In one embodiment, an apparatus comprises a dither motor comprising an outer rim; a hub section; and a plurality of reeds that couple the hub section with the outer rim. A first pickoff embedded drive transducer is mounted on a first side of at least one reed. The first pickoff embedded drive transducer includes a first pickoff section, and a first drive section that is separated from the first pickoff section by a first insulative gap. A second pickoff embedded drive transducer is mounted on a second side of the at least one reed in a back-to-back relationship with the first pickoff embedded drive transducer. The second pickoff embedded drive transducer includes a second pickoff section, and a second drive section that is separated from the second pickoff section by a second insulative gap.

Abstract: A system and method for performing surgical procedures within a body cavity, e.g. abdomen, uses a magnetized device is utilized to allow a surgeon to control intra-abdominal organs and objects. The system and method allows a surgeon to perform an intra-abdominal procedure without the need to position surgical tools inside of the body cavity. Additional surgical ports are not necessary as the magnetized device allows the surgeon to retract or position various objects within the abdomen.

Abstract: Apparatus for capturing images while in motion, including at least one CCD camera housed within an aircraft traveling along a flight path, for capturing aerial images of ground terrain, a motor for rotating an axis on which the at least one CCD camera is mounted, and for generating a sweeping back-and-forth motion for a field of view of the at least one CCD camera, the sweeping motion being transverse to the aircraft flight path, and an optical assembly connected to said at least one CCD camera.

Abstract: A light detection and ranging (LIDAR) device scans through a scanning zone while emitting light pulses and receives reflected signals corresponding to the light pulses. The LIDAR device scans the emitted light pulses through the scanning zone by reflecting the light pulses from an array of oscillating mirrors. The mirrors are operated by a set of electromagnets arranged to apply torque on the mirrors, and an orientation feedback system senses the orientations of the mirrors. Driving parameters for each mirror are determined based on information from the orientation feedback system. The driving parameters can be used to drive the mirrors in phase at an operating frequency despite variations in moments of inertia and resonant frequencies among the mirrors.

Abstract: A tunable reference cavity (3) with two independently controllable mirrors (15, 16) is disclosed. The mirrors are mounted on respective piezoelectric crystals (18, 19) so that thermal expansion of the piezoelectric crystals moves the cavity mirrors in the same direction along a longitudinal axis of the reference cavity thereby reducing a change of the cavity length. Also disclosed is a system for locking and scanning the output of a laser cavity (2). An error signal is generated between an output of the laser cavity (28) and the transmission (28) of the laser through the external reference cavity (3). A dual piezo-actuated mirror (6b) permits processing of the error signal (26) with separate signal processing circuits (29a, 29b) used to provide an electrical feedback signal to the dual piezoelectric crystal (22, 23b).

Abstract: A ring laser gyroscope includes active cavity containing gain medium, first reflective surfaces coupled to active cavity, medium exciter to excite gain medium, second reflective surfaces coupled to first passive cavity, and third reflective surfaces coupled to second passive cavity. Excited gain medium induces first and second laser fields within active cavity. First plurality of reflective surfaces includes first, second, and third reflective surfaces that reflect light within active cavity. Second plurality of reflective surfaces includes first, fourth, and fifth reflective surfaces that reflect light within first passive cavity. Third plurality of reflective surfaces includes fourth, sixth, and seventh reflective surfaces that reflect light within second passive cavity. First and fourth reflective surfaces are partially transmissive such that they both transmit and reflect light.

Abstract: Cavity enhanced absorption spectroscopy systems and methods for detecting trace gases. When the frequency of laser light approaches the frequency of a resonance cavity mode, the laser begins to fill the cavity to that mode. Optical intensity inside the cavity reflects total cavity loss when the laser light frequency coincides with the cavity mode transmission peak. The intra-cavity optical power also depends on the coupling efficiency of the laser beam to the particular cavity mode. Measurement of intensities of three optical signals, namely, intensity of the light incident on to the cavity, intensity of the light reflected from the cavity, and intensity of the intra-cavity optical power, with their appropriate normalization advantageously significantly reduce effects of baseline calibration and drift as the normalized signal only depends on total cavity loss, and not the coupling efficiency, as in traditional approaches.

Abstract: One embodiment of a ring laser gyroscope discussed herein includes a cavity containing a gain medium having a first linewidth, a first plurality of reflective surfaces coupled to the cavity, and at least one medium exciter operable to excite the gain medium. The first plurality of reflective surfaces includes at least first, second, and third reflective surfaces. The first, second, and third reflective surfaces are positioned to reflect light along a path defined in the cavity between the plurality of reflective surfaces. The excited gain medium induces first and second laser fields within the cavity. A portion of the cavity contains an absorption medium having a second linewidth that is narrower than the first linewidth of the gain medium. The absorption medium reduces the gain of the first and second laser fields at a first range of frequencies.

Abstract: A ring laser gyroscope that includes a cavity containing a gain medium, a first plurality of reflective surfaces coupled to the cavity, a medium exciter operable to excite the gain medium, and a saturation beam source operable to emit a saturation beam. The first plurality of reflective surfaces includes a first reflective surface, a second reflective surface, and a third reflective surface. The first, second, and third reflective surfaces are positioned to reflect light along a path defined in the cavity between the plurality of reflective surfaces. The excited gain medium induces first and second laser fields within the cavity. The emitted saturation beam intersects with the first and second laser fields at a first interaction region of the cavity. The saturation beam interacts with the gain medium to reduce the gain of the first and second laser fields at a first range of frequencies.

Abstract: Optical feedback assisted cavity enhanced absorption spectroscopy systems and methods for measuring trace gases with improved long-term stability and reproducibility include a laser coupled with a resonant optical cavity containing a gaseous medium and having at least two cavity mirrors and a plurality of optical resonance cavity modes. The laser emits continuous wave laser light with a mean optical frequency of the laser being adjustable over a range of frequencies, and the laser is responsive to optical feedback light emerging from the cavity. The transmissivity of at least one of the cavity mirrors is selected such that the intensity of the optical feedback light impinging on the laser is below a threshold intensity value so as to ensure that a frequency hold interval range of the optical frequency of the laser is smaller than a free spectral range of the cavity.

Abstract: A interferometric optical gyroscope includes an active resonator comprising a half cavity vertical cavity surface emitting laser (half-VCSEL) operating as one of the mirrors that form the ring resonator. The half-VCSEL includes a bottom mirror stack and active layers formed on the bottom mirror stack and has a surface opposite the bottom mirror stack. Lack of a top mirror stack typically found in a VCSEL prevents the half-VCSEL from lasing, thus the half-VCSEL forms a reflective amplifier for the light circulating in the resonator. A single or multiple external light sources can be used to induce two counter-propagating beams in the resonator. Higher finesse due to the internal gain in the resonator enhances the sensitivity of the gyroscope.

Abstract: One embodiment of a ring laser gyroscope discussed herein includes a cavity containing a gain medium having a first linewidth, a first plurality of reflective surfaces coupled to the cavity, and at least one medium exciter operable to excite the gain medium. The first plurality of reflective surfaces includes at least first, second, and third reflective surfaces. The first, second, and third reflective surfaces are positioned to reflect light along a path defined in the cavity between the plurality of reflective surfaces. The excited gain medium induces first and second laser fields within the cavity. A portion of the cavity contains an absorption medium having a second linewidth that is narrower than the first linewidth of the gain medium. The absorption medium reduces the gain of the first and second laser fields at a first range of frequencies.

Abstract: A ring laser gyroscope that includes a cavity containing a gain medium, a first plurality of reflective surfaces coupled to the cavity, a medium exciter operable to excite the gain medium, and a saturation beam source operable to emit a saturation beam. The first plurality of reflective surfaces includes a first reflective surface, a second reflective surface, and a third reflective surface. The first, second, and third reflective surfaces are positioned to reflect light along a path defined in the cavity between the plurality of reflective surfaces. The excited gain medium induces first and second laser fields within the cavity. The emitted saturation beam intersects with the first and second laser fields at a first interaction region of the cavity. The saturation beam interacts with the gain medium to reduce the gain of the first and second laser fields at a first range of frequencies.

Abstract: A laser gyro having a solid-state amplifying medium and an optical ring cavity includes an assembly encompassing the optical cavity and able to experience an oscillating rotational motion, as well as at least one external optical device for longitudinal injection of energy into the solid-state amplifying medium. The laser gyro also includes a fixing assembly adapted for translationally and rotationally binding said assembly encompassing the optical cavity and said external optical device for longitudinal injection of energy.

Abstract: An embodiment of the invention enhances the rotation sensitivity and decreases the dead band width of a standard HeNe ring laser gyroscope (RLG), with the highest enhancement at low rotation rates. The addition of a gas with nuclear spin to the traditional HeNe gain medium is used to create the intracavity gain medium with an anomalous dispersive quality and thus enhanced rotation sensitivity.

Abstract: An embodiment of the invention enhances the rotation sensitivity and decreases the dead band width of a standard HeNe ring laser gyroscope (RLG), with the highest enhancement at low rotation rates. The addition of a gas with nuclear spin to the traditional HeNe gain medium is used to create the intracavity gain medium with an anomalous dispersive quality and thus enhanced rotation sensitivity.

Abstract: A piezoelectric transducer is described that is configured for use within a path length control apparatus of an optical device. The transducer comprises at least one void formed within a central region of the piezoelectric transducer, the one void or alternatively, the multiple voids, utilized at least in part to limit a curvature induced into a mirror during operation of the piezoelectric transducer.

Abstract: Methods and apparatus are provided for a low cost optical gyro using thin film waveguides to direct light beams among the components of the gyro. The gyro includes a substrate having an insulator layer, a silicon waveguide formed on the insulator layer, and a resonator coupled to the silicon waveguide and configured to circulate a portion of a first light beam in a first counter-propagating direction and circulate a portion of a second light beam in a second counter-propagating direction. The first silicon waveguide propagates the first and second light beams therethrough. Each of the first and second light beams has a resonance frequency when circulating in the resonator.

Abstract: A ring laser gyroscope includes a first plasma shunt arranged to prevent the plasma from contacting a first mirror in the gain region and a second plasma shunt arranged to prevent the plasma from contacting a second mirror in the gain region. The first and second plasma shunts may comprise electrical conductors located in the respective mirror wells and arranged such that contact between the plasma and the electrical conductors quenches the plasma in the mirror wells and produces electrical currents that travels across the mirror wells. The electrical conductors may be formed as metallized strips arranged to extend across the mirror wells, or they may be formed from metal wires. The plasma shunts may alternatively comprise diversion passages formed in the frame and arranged such that the plasma fills the diversion passages and bypasses the mirrors.

Abstract: The present invention relates to a laser gyro of the type comprising an optical block comprising three communicating resonant optical cavities which form a regular octahedron having eight triangular sides, each of the cavities presenting four capillary segments forming a square perpendicular to a corresponding sensitive axis, these cavities being arranged so that each of the angles of one cavity coincides and communicates with the angle of another cavity, a mirror associated with each pair of coinciding angles being oriented so as to be used by the two cavities forming said pair, each cavity using four mirrors including a reading mirror and a cavity-length servo mirror, said gyro also comprising an activation mechanism for driving the block according to a reciprocating rotation movement about an activation axis, and it is characterized in that this gyro comprises three cathodes each linked to two cavities out of the three, these two cavities being each time taken by circular permutation.

Abstract: A piezoelectric transducer is described that is configured for use within a path length control apparatus of an optical device. The transducer comprises at least one void formed within a central region of the piezoelectric transducer, the one void or alternatively, the multiple voids, utilized at least in part to limit a curvature induced into a mirror during operation of the piezoelectric transducer.

Abstract: A path length control driver for a ring laser gyroscope includes a baseplate, a number of piezoelectric elements, and electrodes. The baseplate includes openings selectively sized and located on the baseplate for reducing distortion thereof during thermal or other mechanical loading. The baseplate includes a central hub extending from a central portion of an actuator plate, which comprises an annular diaphragm member. The baseplate further includes an outer rim or sidewall coupled to the actuator plate and a baseplate flange extending from the sidewall. In one embodiment, a portion of the baseplate flange is attached to a mirror transducer substrate assembly. The mirror transducer substrate assembly includes a reflective device, such as a mirror, and a transducer block. The transducer block includes an optical contact surface onto which the mirror is affixed.