Abstract: An optical system uses a sample medium disposed within an optical cavity, receives an input beam that may be non-coherent or coherent, and produces an optical energy from the input beam, by creating birefringent-induced beam components each cavity traversal, forming a mixed quantum state beam for the input beam. The mixed quantum state beam exits the cavity, and the energy distribution of the exiting beam is analyzed over a range of tuned input beam frequencies to uniquely identify circularly birefringent the materials within the sample medium, e.g., amino acids, proteins, or other circular birefringent molecules, biological or otherwise.

Abstract: An ellipsometer includes a light source, a polarizer, an asymmetric wavelength retarder, an analyzer and an optical detection component. The light source is configured to provide a light beam having multiple wavelengths incident to a sample. The polarizer is disposed between the light source and the sample, and configured to polarize the light beam. The asymmetric wavelength retarder is configured to provide a varied retardation effect on the light beam varied by wavelength. The analyzer is configured to analyze a polarization state of the light beam reflected by the sample. The optical detection component is configured to detect the light beam from the analyzer.

Abstract: An ellipsometer includes a light source, a polarizer, an asymmetric wavelength retarder, an analyzer and an optical detection component. The light source is configured to provide a light beam having multiple wavelengths incident to a sample. The polarizer is disposed between the light source and the sample, and configured to polarize the light beam. The asymmetric wavelength retarder is configured to provide a varied retardation effect on the light beam varied by wavelength. The analyzer is configured to analyze a polarization state of the light beam reflected by the sample. The optical detection component is configured to detect the light beam from the analyzer.

Abstract: A fiber-optic gyroscope is disclosed, wherein the fiber-optic gyroscope has counter-propagating light signals in a closed-loop optical path, and where the light signals are characterized by an orthogonality that mitigates optical coupling between them. In some embodiments, the orthogonality is a difference in frequency of the two signals. In some embodiments, the orthogonality is a difference in the polarizations of the two signals. The orthogonality is imparted on the light signals by a non-reciprocal element that is optically coupled with the optical path. In some embodiments, a gain-balancing filter is also included to ensure that the loop gain for each light signal is substantially equal to one. In some embodiments, the light signals are provided by a gain element that is characterized by inhomogeneous broadening.

Abstract: A pulse multiplier includes a polarizing beam splitter, a wave plate, and a set of mirrors. The polarizing beam splitter receives an input laser pulse. The wave plate receives light from the polarized beam splitter and generates a first set of pulses and a second set of pulses. The first set of pulses has a different polarization than the second set of pulses. The polarizing beam splitter, the wave plate, and the set of mirrors create a ring cavity. The polarizing beam splitter transmits the first set of pulses as an output of the pulse multiplier and reflects the second set of pulses into the ring cavity. This pulse multiplier can inexpensively reduce the peak power per pulse while increasing the number of pulses per second with minimal total power loss.

Abstract: A polarimeter for measuring chirality of a material comprising an optical ring cavity comprising a plurality of reflective elements configured to promote bi-directional propagation of a laser beam within the cavity, a laser-emitting device configured to introduce a first input laser beam and a second input laser beam into the ring cavity, and a Faraday rotator and a phase compensator configured to suppress a birefringent background as the first and second laser beams pass through the ring cavity, wherein the plurality of mirrors, Faraday rotator, and phase compensator are configured such that light from the first and second laser beams passes through a chiral material located within the cavity a sufficient number of times for a measurement of optical rotary dispersion (ORD) and circular dichroism (CD) of light transmitted through the chiral material to be obtained. Particular implementations include monolithic ring cavities or microresonators or use of intra-cavity gain media.

Abstract: A ring laser gyroscope (RLG) includes moveable mirrors and a Micro-Electro-Mechanical Systems (MEMS) actuator coupled to the moveable mirrors to cause a respective displacement thereof that induces a phase modulation on counter-propagating light beams relative to one another. The induced phase modulation creates an optical path difference between the counter-propagating light beams corresponding to a virtual rotation that reduces the lock-in of the RLG.

Abstract: Laser devices are presented in which a graphene saturable absorber and an optical amplifier are disposed in a resonant optical cavity with an optical or electrical pump providing energy to the optical amplifier.

Abstract: A ring laser gyro with no piezoelectric elements for dither detection includes a laser beam receiving unit for receiving a laser beam taken out of a gyro block, a laser beam intensity measuring unit for measuring the intensity of the laser beam received by the laser beam receiving unit, a dither mechanism, a dither control unit for driving the dither mechanism, and a gyro case housing the gyro block, wherein the laser beam receiving unit is secured to the gyro case, the laser beam receiving unit has a laser beam receiving surface for receiving the laser beam from the gyro block to detect a laser beam receiving position on the laser beam receiving surface and output positional information indicating the laser beam receiving position. The dither control unit drives the dither mechanism on the basis of information indicating the amplitude of the laser beam receiving position obtained from the positional information.

Abstract: A gyrolaser with optical cavity includes a plurality of mirrors, at least one photo-detector delivering two optical signals in phase quadrature, said signals being digitized. The position of one of said mirrors is controlled by conversion of an electrical signal into a mechanical force. The gyrolaser is activated in an oscillatory movement by conversion of an oscillation electrical signal into a mechanical force. The angular velocity of said gyrolaser is measured, and the phase ? and the modulus ? or the square of the modulus ? are extracted from said optical signals.

Abstract: The field of the invention is that of solid-state laser gyros used for the measurements of rotation speed or relative angular positions. This type of equipment is notably used for aeronautical applications. The object of the invention is to complete the optical devices necessary to control the instability of lasers by specific optical devices enabling elimination of the dead zone and of population inversion gratings exiting in the amplifying medium. An “all optical” solid-state laser is hence obtained without moveable parts, stable and without a dead zone. To this end, the laser gyro according to the invention comprises notably and optical assembly enabling a nonreciprocal optical phase-shift to be introduced between the counterpropagating modes; and control means allowing the phase-shift amplitude to be varied periodically around a mean value that is very approximately zero.

Abstract: The field of the invention is that of solid-state laser gyros. One of the major problems inherent in this technology is that the optical cavity of this type of laser gyro is by nature highly unstable. To reduce this instability, controlled optical are introduced into the cavity that depend on the direction of propagation by using acoustooptic devices. Several devices are described, employing different configurations of acoustooptic devices. These devices apply in particular to laser gyros having monolithic cavities, and in particular to neodymium-doped YAG laser gyros.

Abstract: A method of stabilizing beam power in a ring LASER gyroscope (RKG) during high vibration is provided. The method comprises modifying an electrical signal output from an RLG photodetector to generate a direct current (DC) feedback signal, the DC levels of the feedback signal being proportional to RLG beam power. The method further comprises comparing the DC levels of the feedback signal to a DC reference signal, wherein the DC levels of the reference signal are proportional to a desired RLG beam power level. The method also comprises generating a difference signal representing a difference signal representing a difference between the DC levels of the reference signal and the feedback signal and adjusting RLG beam power based on the difference signal.

Abstract: A ring laser gyroscope or other motion sensor is dithered at a first rate if a global positioning signal is available and/or when alignment is not being performed, and is dithered at a second rate if a global positioning signal is not available and/or when alignment is being performed. The second rate is greater than the first rate.

Abstract: The invention is a compact optical gyroscope based on the Sagnac effect that combines a micro-ring cavity laser comprising a magneto-optical material and a magnetic field to circumvent the lock-in phenomenon at low rates of rotation. The invention also embodies novel processes for breaking lock-in using a transverse Faraday effect.

Abstract: A dither control system for a laser gyro having a dither motor for dithering the laser gyro through a desired angular displacement, known as the command angle, in response to a drive signal. In order to help avoid saturation of the laser gyro, the dither control system reduces the command angle by command angle reduction data when the average drive signal applied to the dither motor exceeds a maximum drive value until the command angle reduction data reaches zero. The command angle reduction value is calculated by integrating the difference between the average drive signal and the maximum drive value.

Abstract: A gyro includes a laser device for generating a first and second laser beams to be propagated circuitally in opposition directions. An electric signal is taken out from the laser device. A third laser beam having an oscillation frequency different from that of the first laser beam is led to enter the laser device so as to be propagated circuitally in the same direction as the first laser beam.