Abstract: The subject matter of this specification can be implemented in, among other things, systems and methods of optical sensing that utilize optimized processing of multiple sensing channels for efficient and reliable scanning of environments. The optical sensing includes multiple optical communication lines that include coupling portions configured to facilitate efficient collection of various received beams. The optical sensing system further includes multiple light detectors configured to process collected beams and produce data representative of a velocity of an object that generated the received beam and/or a distance to that object.

Abstract: A high bandwidth gravimeter or accelerometer includes laser(s), modulator(s), and an atomic interferometer. The laser(s) and modulator(s) produce four laser frequencies. A first and second pair of laser frequencies are each separated by wm. The first and second pair are offset by wshift. A first laser frequency of the first pair and a second laser frequency of the second pair are separated by wm+wshift. A second laser frequency of the first pair and a first laser frequency of the second pair are separated by wm?wshift. The first pair is routed to arrive from a first direction at atoms in an interaction region, and the second pair from a second direction. The first pair are phase stable with respect to the second pair. wm is adjusted so that wm+wshift or wm?wshift corresponds to a Raman resonance for the atomic interferometer.

Abstract: The subject matter of this specification can be implemented in, among other things, systems and methods of optical sensing that utilize time and frequency multiplexing of sensing signals. Described are, among other things, a light source subsystem to produce a first beam having a first frequency and a second beam having a second frequency, a modulator to impart a modulation to the second beam, and an optical interface subsystem to receive a third beam caused by interaction of the first beam with an object and a fourth beam caused by interaction of the second beam with the object. Also described are one or more circuits to determine, based on a first phase information carried by the third beam, a velocity of the object, and then determine, based on a second phase information carried by the third beam and the first phase information, a distance to the object.

Abstract: The subject matter of this specification can be implemented in, among other things, systems and methods that enable lidar channel multiplexing using optical locking of separate lasers while simultaneously imparting different frequency offsets to beams output by different lasers. As a result, received beams reflected from various objects, which are present in an outside environment, can have Doppler-shifted frequencies that do not overlap, facilitating concurrent identification of distances to and velocities of multiple objects.

Abstract: The subject matter of this specification relates to a light detection and ranging (LiDAR) device that comprises, in some implementations, a pulsed-laser source configured to generate a pulsed optical signal, a continuous wave (CW) laser source configured to generate a CW optical signal, one or more optical amplifier circuits configured to amplify at least the pulsed optical signal, a combiner configured to combine the pulsed optical signal and the CW optical signal into a hybrid transmission signal, and at least one photodetector configured to receive a reflection signal produced by reflection of the hybrid transmission signal by a target.

Abstract: A system for an atomic interferometer includes a laser control system and a feedback control system. The laser control system controls a first pointing angle of a first interrogating laser beam. The first interrogating laser beam and a second interrogating laser beam interrogate a pair of almost counter-propagating laser cooled atomic ensembles. The feedback control system adjusts the first pointing angle based at least in part on an inertial measurement using the atomic interferometer to bias an output of the atomic interferometer to compensate for the effects of rotations. The pointing angle of the laser beam, which is linearly related to a frequency used to drive an acousto-optic deflector, is linearly related to the rotation rate of the sensor.

Abstract: A light pulse interferometer includes a first atom source and a first laser. The first atom source is configured to direct a first group of atoms in a first direction. The first laser is configured to generate one or more interferometer laser beam pairs. The one or more interferometer laser beam pairs interact with the first group of atoms in an interferometer sequence of three or more pulses to produce atom interference. A first laser beam pair of the one or more interferometer laser beam pairs is disposed to interact with the first group of atoms to perform 1D-cooling and velocity control of the first group of atoms prior to the interferometer sequence.

Abstract: A conveyor oven having a first mode of operation and a second mode of operation is provided. The conveyor oven generally includes an oven chamber in which food is cooked, a conveyor movable to convey the food through the oven chamber, a burner to generate heat for the oven chamber, at least one blower to circulate air within the oven chamber, and a controller. The burner has a combustion airflow rate, and operates at a first output during the first mode of operation and at a second output that is greater than the first output during the second mode of operation. The blower operates at a first speed during the first mode of operation and at a second speed that is faster than the first speed during the second mode of operation.

Abstract: A conveyor oven having a first mode of operation and a second mode of operation is provided. The conveyor oven generally includes an oven chamber in which food is cooked, a conveyor moveable to convey the food through the oven chamber, a burner to generate heat for the oven chamber, the burner having a combustion airflow rate, at least one blower to circulate air within the oven chamber, and a controller. The blower operates at a first speed during the first mode of operation and at a second speed that is faster than the first speed during the second mode of operation. The controller is responsive to at least one of a burner output and an internal temperature of the oven chamber, and adjusts the combustion airflow rate based in part on at least one of the burner output and the internal temperature of the oven chamber.

Abstract: The device for producing laser-cooled atoms comprises a two dimensional trap or a three-dimensional trap, or a combination of two- and three-dimensional traps. The two-dimensional trap comprises: three or more permanent magnets arranged around a perimeter of a loop, wherein a plane of the loop is perpendicular to a free axis of the two-dimensional atom trap, and the three or more permanent magnets bracket an internal volume of the two-dimensional atom trap; and one or more laser beam input ports enabling access for one or more laser beams to the internal volume of the two-dimensional atom trap.

Abstract: The device for producing laser-cooled atoms comprises a two dimensional trap or a three-dimensional trap, or a combination of two- and three-dimensional traps. The two-dimensional trap comprises: three or more permanent magnets arranged around a perimeter of a loop, wherein a plane of the loop is perpendicular to a free axis of the two-dimensional atom trap, and the three or more permanent magnets bracket an internal volume of the two-dimensional atom trap; and one or more laser beam input ports enabling access for one or more laser beams to the internal volume of the two-dimensional atom trap.

Abstract: The device for producing laser-cooled atoms comprises a two dimensional trap or a three-dimensional trap, or a combination of two- and three-dimensional traps. The two-dimensional trap comprises: three or more permanent magnets arranged around a perimeter of a loop, wherein a plane of the loop is perpendicular to a free axis of the two-dimensional atom trap, and the three or more permanent magnets bracket an internal volume of the two-dimensional atom trap; and one or more laser beam input ports enabling access for one or more laser beams to the internal volume of the two-dimensional atom trap.

Abstract: A self-cleaning, gas-fired tunnel oven is provided. One embodiment of the oven provides a self-cleaning, gas-fired tunnel oven for cooking food products. The oven includes a control system that regulates oven temperature during a pyrolitic, self-cleaning procedure for incinerating contaminants that accumulate inside; a burner for cooking food products and incinerating contaminants; a modulating air and fuel control system arranged for proportionally delivering air and fuel to the burner; a plurality of convection air fingers for directing heated air toward the food products; a collapsible conveyor, capable of fitting into the oven when collapsed, for passing the food products through the oven; a plurality of blowers, each having a dedicated speed controller; a floating cooking chamber; and a vent system that maintains a negative pressure in the oven during the self-cleaning procedure.

Abstract: A conveyor oven having a first mode of operation and a second mode of operation is provided. The conveyor oven generally includes an oven chamber in which food is cooked, a conveyor moveable to convey the food through the oven chamber, a burner to generate heat for the oven chamber, the burner having a combustion airflow rate, at least one blower to circulate air within the oven chamber, and a controller. The blower operates at a first speed during the first mode of operation and at a second speed that is faster than the first speed during the second mode of operation. The controller is responsive to at least one of a burner output and an internal temperature of the oven chamber, and adjusts the combustion airflow rate based in part on at least one of the burner output and the internal temperature of the oven chamber.

Abstract: A self-cleaning, gas-fired tunnel oven is provided. One embodiment of the oven provides a self-cleaning, gas-fired tunnel oven for cooking food products. The oven includes a control system that regulates oven temperature during a pyrolitic, self-cleaning procedure for incinerating contaminants that accumulate inside; a burner for cooking food products and incinerating contaminants; a modulating air and fuel control system arranged for proportionally delivering air and fuel to the burner; a plurality of convection air fingers for directing heated air toward the food products; a collapsible conveyor, capable of fitting into the oven when collapsed, for passing the food products through the oven; a plurality of blowers, each having a dedicated speed controller; a floating cooking chamber; and a vent system that maintains a negative pressure in the oven during the self-cleaning procedure.

Abstract: A detection system for monitoring an engineered structure includes an array of sensors disposable in a predetermined pattern on the engineered structure and disposable between a surface of the engineered structure and a protective coating substantially covering the surface. The detection system also includes a data acquisition system in communication with the array of sensors for retrieving data from the sensors. The array of sensors can provide data corresponding to at least one of a degree of cure of the protective coating, a health of the cured protective coating, and a corrosion rate of the engineered structure at each of the sensors.

Abstract: Charbroilers, such as conveyorized and batch charbroilers, are disclosed wherein a single pilot flame receives gas from a gas line and is operable to ignite a plurality of burners. The charbroiler may include a housing, a conveyor removable from the housing and a shielding member removably connectable to the housing or burner and positioned between the burner and food product. The shielding member may be coated with a ceramic material and may have a color relating to a property of at least one of the shielding member and the ceramic material. In addition, the charbroiler may include a first burner and a second burner having different heating capacities. The charbroiler may also include an upper burner and lower burner positioned respectively above and below the food product and each of the upper and lower burners includes a ceramic diaphragm.

Abstract: A tunable interferometer for creating gratings of variable periodicity in an optical waveguide is disclosed. The interferometer includes a beam splitter for producing first and second write beams from an input beam. First and second reflectors receive the first and second write beams, respectively, from the beam splitter and direct the first and second write beams to intersect at a fixed location. The angle of intersection of the first and second write beams is a function of impingement locations of the first and second write beams on the first and second reflectors. The impingement locations of the first and second write beams on the first and second. reflectors may be varied to vary the angle of intersection at the fixed location.

Abstract: A device and method in accordance with the present invention align the polarization of an incoming light wave to the principal axis of a polarization maintaining (PM) optical fiber. Light is launched from the broadband source travels through a beam splitter to a polarizer, a polarization control device, a signal transmission medium and a birefringent medium having at least one partially reflective region including a cleaved and polished end face of the fiber or a Bragg grating written into a length of PM fiber. The reflected light is then used to align the polarization of the light to the birefringent axis of the PM fiber.

Abstract: A method for screening the quality of an optical component including the step of simulating the performance of the optical component. The step of simulating includes the step of measuring the optical phase &phgr; of the optical component, wherein the step of measuring comprises indirectly measuring the optical phase &phgr; of the optical component using a scanning laser having a scanning step size &Dgr;&ohgr; and a modulation frequency &ohgr;m such that &Dgr;&ohgr;/&ohgr;m≦2. The light throughput R of the optical component is then measured. A transfer function H as a function of optical frequency &ohgr; is constructed where H(&ohgr;)=R(&ohgr;)exp[j&phgr;(&ohgr;)], and the performance is simulated using the measured value of the optical phase and the light throughput into the transfer function.