Abstract: An apparatus includes a plurality of front-end nonlinear optical crystals and a plurality of back-end nonlinear optical crystals. The front-end nonlinear optical crystals are arranged in a chain and are configured to amplify a received signal. The back-end nonlinear optical crystals are arranged in the chain after the front-end nonlinear optical crystals and are configured to further amplify the received signal and generate an amplified signal. The back-end nonlinear optical crystals are made from a different nonlinear optical crystal than the front-end nonlinear optical crystals.

Abstract: An apparatus includes a plurality of front-end nonlinear optical crystals and a plurality of back-end nonlinear optical crystals. The front-end nonlinear optical crystals are arranged in a chain and are configured to amplify a received signal. The back-end nonlinear optical crystals are arranged in the chain after the front-end nonlinear optical crystals and are configured to further amplify the received signal and generate an amplified signal. The back-end nonlinear optical crystals are made from a different nonlinear optical crystal than the front-end nonlinear optical crystals.

Abstract: Spectral beam combining systems including a multi-element transform optic. In certain examples the multi-element transform optic includes a first cylindrical optical element having positive optical power in a first axis, a second optical element having negative optical power in the first axis, and a third toroidal optical element having positive optical power in the first axis and either positive or negative optical power in a second axis that is orthogonal to the first axis. The first and third optical elements are positioned on opposite sides of the second optical element and equidistant from the second optical element. The multi-element transform optic has an optical path length extending between a front focal plane and a back focal plane that is shorter than an effective focal length of the multi-element transform optic.

Abstract: Spectral beam combining systems including a multi-element transform optic. In certain examples the multi-element transform optic includes a first cylindrical optical element having positive optical power in a first axis, a second optical element having negative optical power in the first axis, and a third toroidal optical element having positive optical power in the first axis and either positive or negative optical power in a second axis that is orthogonal to the first axis. The first and third optical elements are positioned on opposite sides of the second optical element and equidistant from the second optical element. The multi-element transform optic has an optical path length extending between a front focal plane and a back focal plane that is shorter than an effective focal length of the multi-element transform optic.

Abstract: Generally discussed herein are systems, devices, and methods for locking an optical frequency comb. A device may include comb error measurement and control circuitry to receive a beat tone and carrier envelope offset of an optical frequency comb and provide a fast and slow repetition rate control and a fast and slow carrier envelope offset control. The repetition rate controls and carrier envelope offset controls to control actuators of an optical frequency comb generator.

Abstract: Generally discussed herein are systems, devices, and methods for providing a frequency stabilized optical frequency comb, including frequency stabilizing the optical frequency comb to a laser that is frequency stabilized to an optical reference cavity, generating a low frequency electrical signal from the optical frequency comb, comparing the generated low frequency electrical signal to a reference low frequency electrical signal, determining an optical reference cavity drift based on the comparison, and then adjusting a frequency of the laser in response to the determined optical reference cavity drift.

Abstract: A system for distributing a reference oscillator signal includes a clock having a reference oscillator and a femtosecond laser stabilized by the reference oscillator. The system also includes at least one beamsplitter configured to split the femtosecond laser. The system further includes one or more remote nodes that are spaced from the clock. The remote nodes are configured to generate reference signals based on the split femtosecond laser.

Abstract: Embodiments of an ultra-stable frequency reference generating system and methods for generating an ultra-stable frequency reference using a two-photon Rubidium transition are generally described herein. In some embodiments, a cavity-stabilized reference laser comprising a laser source is locked to a stabilized cavity. A Rubidium cell is interrogated by a stabilized laser output to cause at least a two-photon Rubidium transition and a detector may detect fluorescence resulting from spontaneous decay of the upper state Rubidium transition. The output of the detector is provided at a wavelength of the fluorescence to lock the cavity-stabilized reference laser to generate a stabilized laser output. A frequency comb stabilizer may be locked to the stabilized laser output to generate a super-continuum of optical wavelengths for use in generating an ultra-stable frequency reference.

Abstract: Embodiments of an ultra-stable frequency reference generating system and methods for generating an ultra-stable frequency reference using a two-photon Rubidium transition are generally described herein. In some embodiments, a cavity-stabilized reference laser comprising a laser source is locked to a stabilized cavity. A Rubidium cell is interrogated by a stabilized laser output to cause at least a two-photon Rubidium transition and a detector may detect fluorescence resulting from spontaneous decay of the upper state Rubidium transition. The output of the detector is provided at a wavelength of the fluorescence to lock the cavity-stabilized reference laser to generate a stabilized laser output. A frequency comb stabilizer may be locked to the stabilized laser output to generate a super-continuum of optical wavelengths for use in generating an ultra-stable frequency reference.

Abstract: Embodiments of an ultra-stable frequency reference generating system and methods for generating an ultra-stable frequency reference using a two-photon Rubidium transition are generally described herein. In some embodiments, a cavity-stabilized reference laser comprising a laser source is locked to a stabilized cavity. A Rubidium cell is interrogated by a stabilized laser output to cause at least a two-photon Rubidium transition and a detector may detect fluorescence resulting from spontaneous decay of the upper state Rubidium transition. The output of the detector is provided at a wavelength of the fluorescence to lock the cavity-stabilized reference laser to generate a stabilized laser output. A frequency comb stabilizer may be locked to the stabilized laser output to generate a super-continuum of optical wavelengths for use in generating an ultra-stable frequency reference.

Abstract: A system for distributing a reference oscillator signal includes a clock having a reference oscillator and a femtosecond laser stabilized by the reference oscillator. The system also includes at least one beamsplitter configured to split the femtosecond laser. The system further includes one or more remote nodes that are spaced from the clock. The remote nodes are configured to generate reference signals based on the split femtosecond laser.

Abstract: A system for distributing a reference oscillator signal includes a clock having a reference oscillator and a femtosecond laser stabilized by the reference oscillator. The system also includes at least one beamsplitter configured to split the femtosecond laser. The system further includes one or more remote nodes that are spaced from the clock. The remote nodes are configured to generate reference signals based on the split femtosecond laser.

Abstract: Embodiments of an ultra-stable frequency reference generating system and methods for generating an ultra-stable frequency reference using a two-photon Rubidium transition are generally described herein. In some embodiments, a cavity-stabilized reference laser comprising a laser source is locked to a stabilized cavity. A Rubidium cell is interrogated by a stabilized laser output to cause at least a two-photon Rubidium transition and a detector may detect fluorescence resulting from spontaneous decay of the upper state Rubidium transition. The output of the detector is provided at a wavelength of the fluorescence to lock the cavity-stabilized reference laser to generate a stabilized laser output. A frequency comb stabilizer may be locked to the stabilized laser output to generate a super-continuum of optical wavelengths for use in generating an ultra-stable frequency reference.

Abstract: A system for distributing a reference oscillator signal includes a clock having a reference oscillator and a femtosecond laser stabilized by the reference oscillator. The system also includes at least one beamsplitter configured to split the femtosecond laser. The system further includes one or more remote nodes that are spaced from the clock. The remote nodes are configured to generate reference signals based on the split femtosecond laser.

Abstract: An ultra-stable short pulse remote sensor having extended temporal coherence for long range sensing. The sensor provides unique target signatures from an ultrashort pulse after it has interacted with a target at range by measuring the spectral amplitude and phase of the pulse. Accordingly, coherent detection of targets at long ranges can be performed with reduced power.