United States of America As Represented by the Administrator of Nasa

Dorsal Networks, Inc.

Infinera Corporation

Guangning Yang

Jeffrey R Chen

Kim S Jepsen

Mark A Stephen

Kenji Numata

David J Copeland

Stewart T Wu

Yan Han

Hui Li

John Lai

Wei Lu

Marc Placidet

Ulrik Gliese

Avery Van Gieson

Greg Mooney

David Kerr

Mark LaLiberte

The present invention relates to a lidar system including: laser transmitter and receiver systems, the laser transmitter system including: a wavelength-tunable seed laser which emits pulses at selected wavelength points, and switches between wavelengths within a switching time of <200 ns; a fiber amplifier which amplifies the laser pulses up to 200 kW to a transmitter grating; and a transmitter telescope including primary and secondary mirrors. The laser beam is directed from the transmitter grating to the secondary then primary mirrors, and the first transmitter grating is imaged on the primary mirror to minimize laser beam wander thereon. The transmitter grating diffracts and steers the laser beam by wavelength to a surface, to an arbitrary subset of <2000 resolvable footprints along a cross-track direction at a beam pointing angle switching time of <200 ns, such that footprints illuminated by the laser beam on the surface are imaged in 3D.

3-dimensional imaging lidar system

A satellite includes a fast tracking mirror ('mirror') placed at or near center of mass (CoM) of the satellite along a line of sight between the CoMs of two satellites. The satellite also includes a detector at a distance away from the mirror. The mirror is adjusted to maintain the distance between the mirror and the detector, when a location of the detector changes due to pitch and yaw of the satellite.

Active pointing and tracking system

A photonic, integrated circuit chip can have a frequency comb laser configured to generate a plurality of wavelengths, a plurality of modulators, one respective modulator for each wavelength of the plurality of wavelengths, the plurality of modulators being aligned in series with each of the plurality of modulators being tuned to a respective one of the wavelengths of the plurality of wavelengths, a connector configured to convey a drive signal for each modulator of the plurality of modulators, a semiconductor optical amplifier configured to receive light exiting from the plurality of modulators, and a chip having present thereon the frequency comb laser, the plurality of modulators, and the semiconductor optical amplifier. The plurality of modulators can be configured to produce a single beam of time-interleaved, multiple-wavelength output laser light. A mobile system, such as a satellite, can also have the photonic, integrated circuit chip as a component thereof.

Integrated multi-wavelength WDM TDM lidar transmitter

An apparatus for improving a pointing capability of an optical pointing system includes a star tracker attitude control system for maintaining an alignment between the optical pointing system and a target, a beam steering mirror controlled by the star tracker attitude control system to direct an optical signal to impinge on the target, a fixed optical assembly configured to direct a portion of the optical signal from the bean steering mirror into a field of view of a star tracker telescope of the star tracker attitude control system, and a detector array for detecting the portion of the optical signal superimposed over a location in a current star scene in the star tracker telescope field of view, where the star tracker attitude control system is configured to operate the beam steering mirror to maintain the optical signal on the target by maintaining the superimposed signal on the location in the star scene.

Steering mirror assist for laser pointing

An apparatus for measuring a distance between a first and second terminal includes a frame counter for determining a number of data frames traversing a distance between the first terminal 105 and the second terminal, a frame bit counter for determining a number of data clock bits offset between a transmitted data frame and a concurrently received data frame, a data clock phase detector for determining a phase difference between an RF data clock for the transmitted data frame and an RF data clock for the concurrently received data frame, and an optical carrier phase detector for determining a phase difference between an optical carrier used to transmit the transmitted data frame and an optical carrier for the concurrently received data frame. The distance between the first and second terminal is determined from a round trip transit time T between the first and second terminals.

Continuous carrier optical phase optometric measurement over coherent optical communication link

A communication system may include a first control circuit to detect a break on a first optical link; a first optical source to supply a first optical signal on a second optical link in response to detecting the break on the first optical link, the first optical signal propagating in a first direction on the second optical link; a second control circuit to detect a presence of the first optical signal on the second optical link, and output a control signal in response to detecting the presence of the first optical signal; and a second optical source to supply a second optical signal on the second optical link, the second optical signal propagating in a second direction opposite the first direction, where the Raman pump is disabled in response to the control signal.

Automatic laser shutdown and recovery in response to a link break

An apparatus and method is provided to enable precision and fast laser frequency tuning. For instance, a fast tunable slave laser may be dynamically offset-locked to a reference laser line using an optical phase-locked loop. The slave laser is heterodyned against a reference laser line to generate a beatnote that is subsequently frequency divided. The phase difference between the divided beatnote and a reference signal may be detected to generate an error signal proportional to the phase difference. The error signal is converted into appropriate feedback signals to phase lock the divided beatnote to the reference signal. The slave laser frequency target may be rapidly changed based on a combination of a dynamically changing frequency of the reference signal, the frequency dividing factor, and an effective polarity of the error signal. Feed-forward signals may be generated to accelerate the slave laser frequency switching through laser tuning ports.

Apparatus and method to enable precision and fast laser frequency tuning

A system compensates for the presence of power transients. The system receives a data signal and detects the occurrence of a power transient. The system generates a threshold signal based on the detected power transient and determines a value of the data signal based on the threshold signal.

Systems and methods for compensating for signal transients

A method of modulating an optical signal is provided comprising the steps of providing a first electric field in a first optical signal path, providing a second electric field in a second optical signal path, transmitting an optical signal along the first optical signal path and the second optical signal path, amplitude modulating the optical signal via the first electric field and the second electric field, and phase modulating the optical signal via the first electric field and the second electric field. A clock source and a data source are ANDed to provide a data modulated RF signal on an offset waveguide electrode for generating the first and second electric fields. The magnitude of the electric field of the first electric field in the first optical signal path is greater than the magnitude of the electric field of the second electric field in the second optical signal path.

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Clarksville, MD, United States of America

Guangning Yang