Abstract: Apparatus, systems, and methods associated with remote phase and amplitude spectroscopy in frequency, time, and position with correlated frequency combs are applicable in a variety of applications. Multiple beams can be generated from a single laser source, where, in the frequency domain, the multiple beams are frequency combs with equal repetition rates and shifted in frequency from each other. One or more of the multiple beams can be directed to interact with a sample with another one of the multiple beams used as a reference beam. The interaction can include transmission of one of the multiple beams as a signal beam through the sample, reflection of one of the multiple beams as a signal beam from the sample, or backscattering from the sample. Results from the interaction can be analyzed.

Abstract: A nonlinear transmission system comprising a polarization maintaining (PM) fiber and a polarizer, based on the extreme sensitivity of the state of polarization of transmitted light on various parameters, such as the temperature, the optical power input to the fiber. Passive stabilization is achieved by simply terminating the PM fiber by a polarizer at a selected angle. Active stabilization of the optical length of the PM fiber is achieved by feeding back the transmitted into the control of optical power sent through the fiber.

Abstract: Apparatus, systems, and methods associated with enhancement of phase response of intracavity phase interferometers are applicable in a variety of applications.

Abstract: Apparatus, systems, and methods of operating a fiber laser having polarization-preserving fibers can be applied as a sensor to detect a physical quantity. In various embodiments, polarization-preserving fibers can provide a laser cavity having an interferometer disposed in the laser cavity. In various embodiments, a fiber optical parametric oscillator can include an interferometer disposed in the cavity of the optical parametric oscillator. Additional apparatus, systems, and methods are disclosed.

Abstract: Apparatus, systems, and methods of generating multi combs can be used in a variety of applications. In various embodiments, a passive resonator can be disposed in the laser cavity of a mode-locked laser to generate a nested frequency comb. The passive resonator can be a sample under investigation, where a characteristic of the sample is determined using the generated nested frequency comb. Additional apparatus, systems, and methods are disclosed.

Abstract: Apparatus, systems, and methods of operating a fiber laser having polarization-preserving fibers can be applied as a sensor to detect a physical quantity. In various embodiments, polarization-preserving fibers can provide a laser cavity having an interferometer disposed in the laser cavity. In various embodiments, a fiber optical parametric oscillator can include an interferometer disposed in the cavity of the optical parametric oscillator. Additional apparatus, systems, and methods are disclosed.

Abstract: Apparatus, systems, and methods of generating multi combs can be used in a variety of applications. In various embodiments, a passive resonator can be disposed in the laser cavity of a mode-locked laser to generate a nested frequency comb. The passive resonator can be a sample under investigation, where a characteristic of the sample is determined using the generated nested frequency comb. Additional apparatus, systems, and methods are disclosed.

Abstract: In various embodiments, systems and methods can be structured to provide efficient active bidirectional mode-locked lasers, which can be used as intracavity phase interferometer (IPI) sensors. Stable bidirectional mode-locking can be achieved by a combination of a passive mechanism, a passively driven active mechanism, and a beat note detection system. Such systems can be used in guidance, navigation, and control systems, where attitude control of a vehicle relies on accurate measurements of its position and motion. In various embodiments, a detection system can be based on an all fiber intracavity phase interferometer (IPI) active laser capable of delivering accurate simultaneous measurements of all three degrees of rotation and position in a single, compact, cost effective unit. A variation of the same system can include a linear cavity laser for accurate measurements of acceleration without the use of any inertial masses. Additional apparatus, systems, and methods are disclosed.

Abstract: Apparatus, systems, and methods of generating multi combs can be used in a variety of applications. In various embodiments, an etalon can be disposed in the laser cavity of a mode-locked laser to adjust frequency combs. Additional apparatus, systems, and methods are disclosed.

Abstract: Apparatus, systems, and methods having a frequency comb of large spacing can be used in a variety of applications. In various embodiments, a frequency comb is generated from a slave laser by injecting an optical output from a drive laser into the slave laser. One or more parameters of the drive laser and/or the slave laser can be adjusted such that a frequency comb can be generated at a multiple of the repetition rate of the drive laser. Additional apparatus, systems, and methods are disclosed.

Abstract: A Scanning Phase Intracavity Nanoscope as a measurement system can be realized with a reference laser cavity and a sample laser cavity superimposed upon each other to operatively propagate two laser beams. The sample laser cavity is operatively formed by the sample to be measured. A measurement of the sample is based on differences in the reference laser cavity and the sample laser cavity determined from difference in the two laser beams.

Abstract: Apparatus, systems, and methods to construct and operate a radio frequency self-regenerated locked optical oscillator can be used in a variety of applications. Stable synchronization of an optical oscillator can be achieved by driving an amplitude modulator with a radio frequency (RF) signal regenerated from the cavity of the optical oscillator. Additional apparatus, systems, and methods are disclosed.

Abstract: Apparatus, systems, and methods are provided that utilize a material inserted into a laser cavity such that the material has an optical length that varies as the laser cavity varies to keep the repetition rate constant. The material may provide auto-stabilization of the optical output form the laser cavity.

Abstract: Apparatus and methods for providing a drive laser beam to a communication unit responsive to the drive laser beam provide the communication unit the ability to provide femtosecond communication. In an embodiment, the communication unit may be configured as an emitter to provide an optical signal for multiplexing into a transmission medium. In an embodiment, the communication unit includes an a time lens in a configuration that provides separation of optical channel signals from a received optical signal and time expansion of each optical channel signal.

Abstract: Apparatus, systems, and methods are provided that utilize a material inserted into a laser cavity such the material has an optical length that varies as the laser cavity varies to keep the repetition rate constant. The material may provide auto-stabilization of the optical output form the laser cavity.

Abstract: Apparatus and methods for providing a drive laser beam to a communication unit responsive to the drive laser beam provide the communication unit the ability to provide femtosecond communication. In an embodiment, the communication unit may be configured as an emitter to provide an optical signal for multiplexing into a transmission medium. In an embodiment, the communication unit includes an a time lens in a configuration that provides separation of optical channel signals from a received optical signal and time expansion of each optical channel signal.

Abstract: A scatterometer utilizes the dead zone resulting from lockup caused by scatter from a sample located in the optical path of a ring laser at a location where counter-rotating pulses cross. The frequency of one pulse relative to the other is varied across the lockup dead zone.

Abstract: A system and method for launching and characterizing filaments are provided using an aerodynamic window. A filament, a self-induced waveguide in air, is produced by high power laser pulses traversing the atmosphere that can self-focus due to the nonlinear index of refraction of air. At some critical power, self-focusing overcomes diffraction in the atmosphere and the beam collapses until it is balanced by some higher order effect, usually plasma de-focusing. The use of an aerodynamic window provides an opening for a laser beam to propagate between two different atmospheric regions without the use of a solid window, such as between the atmosphere and a vacuum. An aerodynamic window provides a means for controllably launching a filament into the atmosphere. Additionally, an aerodynamic window allows for the characterizing evaluation of a filament without damage to the optical diagnostic tools.

Abstract: A line of sight laser communication system includes a laser to generate a laser signal with femtosecond pulses. A first grating spectrally disperses the femtosecond pulses of the laser signal. A programmable mask converts the femtosecond pulses of the laser signal into coded words. A second grating spectrally recombines the coded words of the laser signal. A telescope then launches the laser signal. The launched laser signal is received at a receiving telescope. A second laser generates a set of reference pulses. A non-linear crystal combines the set of reference pulses and the laser signal to create an output signal only when the laser signal and the reference pulses temporally coincide. A camera records the output signal.

Abstract: A laser communication system includes a first laser to generate a laser signal with femtosecond pulses. A first grating spectrally disperses the femtosecond pulses of the laser signal. A modulator converts the femtosecond pulses of the laser signal into coded words. A second grating spectrally recombines the coded words of the laser signal. A first telescope launches the laser signal. A second telescope receives the laser signal. A second laser generates a set of reference pulses. A non-linear crystal combines the set of reference pulses and the laser signal so as to create an output signal only when the laser signal and the reference pulses temporally coincide. A detector records the output.