Abstract: Embodiments herein describe using a birefringent element (e.g., a half-wave plate, full-wave plate, birefringent crystal, or metasurface) or a band-pass filter to reduce the laser line broadening induced by the soliton self-frequency shift. The birefringent element may a free space element that is part of the laser cavity. Due to dispersion, different frequencies (or colors) of light in the laser travel through the birefringent element at different speeds. This dispersion results in the birefringent element introducing slightly different polarization shifts for the different frequencies of light in the laser. When this light passes through a polarizer (which is set to filter out polarizations different from a desired polarization), the polarizer attenuates or extinguishes the frequencies that do not have the polarization of the design frequency of the birefringent element.

Abstract: Embodiments herein describe peak detection techniques for selecting an absorption line to lock a spectroscopy laser in a frequency reference (e.g., an atomic clock). In one embodiment, an atomic reference is used which has many absorption lines within a relatively small frequency range (e.g., within a gain profile of the spectroscopy laser). The peak detection techniques can evaluate which of these lines a laser can be locked to. For example, the peak detection algorithm can define a preferred absorption line. But if for some reason the spectroscopy laser cannot be locked to the preferred absorption line, the peak detection technique has at least one backup absorption line. By having a set of candidate absorption lines, the peak detection algorithm can identify a suitable absorption line for lasers with different gain regions, or as gain regions change.

Abstract: Embodiments herein describe using a reference laser locked to an atomic reference to adjust the wavelength of a seed laser. A frequency adjuster (e.g., a frequency doubler) can adjust the seed laser to a different wavelength/frequency for a particular application. A controller can adjust the wavelength of the seed laser by comparing the reference laser to the adjusted seed laser generated by the frequency adjuster.

Abstract: Embodiments herein describe spectroscopy systems that provide frequency, amplitude, and power-stabilized light to a vapor cell. An optical signal can be split into two optical paths where a first optical path includes an AOM to perform frequency and amplitude modulation to generate a pump optical signal and a second optical path that includes a variable optical attenuator (VOA) for generating a probe optical signal. These optical signals can then be provided into a vapor cell (also referred to as a gas cell) to perform spectroscopy.

Abstract: Embodiments herein describe a continuous wave two-way optical time two-way transfer system. The embodiments herein lock a local frequency comb to a clock (e.g., optical/microwave atomic clock, Fabry-Perot optical reference cavity, etc.) in a local platform. The platform then generates two CW optical signals with different frequencies and locks those optical signals to the local frequency comb. The local platform then transmits its two CW optical signals to a remote platform and receives CW optical signals (having approximately the same frequencies as the two CW optical signals generated by the local platform) from the remote platform. Based on comparing its local CW optical signals with the received CW optical signals, the local platform can determine a timing deviation between its clock and a clock in the second platform.

Abstract: Embodiments herein describe a path length adjuster for, e.g., adjusting the length of an optical cavity of a laser. In one embodiment, the path length adjuster includes a circulator element for ensuring unidirectional lasing. The path length adjuster may also include one or more focusing elements such as a focusing lens and/or a collimator which directs received laser light at a mirror. The mirror is mounted on an actuator that moves the mirror in a direction parallel with the propagation of the laser light, thereby increasing or reducing the length of the ring cavity.

Abstract: Embodiments herein describe generating signals for stabilizing a frequency comb using a PIC that contains a two-segment supercontinuum generator waveguide (SGW). A first segment of the SGW is designed to spread the spectrum of the frequency comb so that a significant portion of the spectral intensity of the frequency comb is at double the original frequency of the frequency comb. A second segment of the SGW is designed to spread the spectrum of the frequency comb so that a significant portion of the spectral intensity of the frequency comb is at a frequency of a reference laser.

Abstract: Embodiments herein describe spectroscopy systems that use an unmodulated reference optical signal to mitigate noise, or for other advantages. In one embodiment, the unmodulated reference optical signal is transmitted through the same vapor cell as a modulated pump optical signal. As such, the unmodulated reference optical signal experiences absorption by the vapor, which converts laser phase noise to amplitude noise like the other optical signals passing through the vapor cell. In one embodiment, the unmodulated reference optical signal has an optical path in the gas cell that is offset (or non-crossing) from the optical path of the modulated pump optical signal. The unmodulated reference optical signal allows removal or mitigation of the noise on the other optical signal.

Abstract: Various disclosed embodiments include collimated beam atomic ovens, collimated atomic beam sources, methods of loading a source of atoms into an atomic oven, and methods of forming a collimated atomic beam. In some embodiments, an illustrative collimated beam atomic oven includes: a tube having a first portion and a second portion; a source of atoms disposed in the first portion of the tube; an aperture disposed in the second portion of the tube; a heater assembly disposable in thermal communication with the tube; and an openable seal disposed in the tube intermediate the source of atoms and the aperture.

Abstract: Disclosed embodiments include laser systems. An illustrative laser system includes a tunable laser. A beam splitter is operatively couplable to an output of the laser and is configured to split light output from the laser into a first path and a second path. A first modulator is disposed in the first path and is configured to generate first set of sidebands. A bandpass filter circuit includes a fiber Bragg grating filter and is operatively couplable to receive output from the first modulator and to pass a selected sideband of the first set of sidebands. A lock circuit is disposed in the second path, is configured to determine and stabilize wavelength of the laser, and is further configured to cooperate with the fiber Bragg grating filter to maintain a static lock point for the laser while allowing output of the first path to be tunable with respect to the lock point.

Abstract: Embodiments herein describe sub-picosecond accurate two-way clock synchronization by optically combining received optical pulses with optical pulses generated locally in a photonic chip before the optical signals are then detected by a photodetector to obtain an interference measurement. That is, the optical pulses can be combined to result in different interference measurements. Optically combining the pulses in the photonic chip avoids much of the jitter introduced by the electronics. Further, the sites can obtain multiple interference measurements which can be evaluated to accurately determine when the optical pulses arrive at the site with femtosecond accuracy.

Abstract: Embodiments herein describe sub-picosecond accurate two-way clock synchronization by optically combining received optical pulses with optical pulses generated locally in a photonic chip before the optical signals are then detected by a photodetector to obtain an interference measurement. That is, the optical pulses can be combined to result in different interference measurements. Optically combining the pulses in the photonic chip avoids much of the jitter introduced by the electronics. Further, the sites can obtain multiple interference measurements which can be evaluated to accurately determine when the optical pulses arrive at the site with femtosecond accuracy.

Abstract: Various disclosed embodiments include collimated beam atomic ovens, collimated atomic beam sources, methods of loading a source of atoms into an atomic oven, and methods of forming a collimated atomic beam. In some embodiments, an illustrative collimated beam atomic oven includes: a tube having a first portion and a second portion; a source of atoms disposed in the first portion of the tube; an aperture disposed in the second portion of the tube; a heater assembly disposable in thermal communication with the tube; and an openable seal disposed in the tube intermediate the source of atoms and the aperture.

Abstract: Embodiments herein describe sub-picosecond accurate two-way clock synchronization by optically combining received optical pulses with optical pulses generated locally in a photonic chip before the optical signals are then detected by a photodetector to obtain an interference measurement. That is, the optical pulses can have different repetition rates so that the offset between the received and local optical pulses constantly changes, thereby resulting in different interference measurements. Optically combining the pulses in the photonic chip avoids much of the jitter introduced by the electronics. Further, the sites can obtain multiple interference measurements which can be evaluated to accurately determine when the optical pulses arrive at the site with femtosecond accuracy.

Abstract: A system for optical comb carrier envelope offset frequency control includes a mode-locked oscillator. The mode-locked oscillator produces an output beam using an input beam and one or more control signals. The output beam includes a controlled carrier envelope offset frequency. A beat note generator produces a beat note signal using a portion of the output beam. A control signal generator produces the one or more control signals to set the beat note signal by modulating the intensity of the input beam within the mode locked oscillator. Modulating the intensity comprises using a Mach-Zehnder intensity modulator or using an intensity modulated external laser to affect a gain medium within the mode-locked laser.

Abstract: A device for magnetic field generation includes a flux deliverer and a field shaper.

Abstract: A device for magnetic field generation includes a flux deliverer and a field shaper.

Abstract: An atom interferometer device for inertial sensing includes one or more thermal atomic sources, a state preparation laser, a set of lasers, and a detection laser. The one or more thermal atomic sources provide one or more atomic beams. A state preparation laser is disposed to provide a state preparation laser beam nominally perpendicular to each of the one or more atomic beams. A set of lasers is disposed to provide interrogation laser beams that interrogate the one or more atomic beams to assist in generating atom interference. A detection laser is disposed to provide a detection laser beam, which is angled at a first angle to the each of the one or more atomic beams in order to enhance the dynamic range of the device by enabling velocity selectivity of atoms used in detecting the atom interference.

Abstract: A device for magnetic field generation includes a flux deliverer and a field shaper.

Abstract: A system for optical comb carrier envelope offset frequency control includes a mode-locked laser and a frequency shifter. The mode-locked laser produces a laser output. The frequency shifter shifts the laser output to produce a frequency shifted laser output based at least in part on one or more control signals. The frequency shifted laser output has a controlled carrier envelope offset frequency. The frequency shifter includes a first polarization converter, a rotating half-wave plate, and a second polarization converter.