A multi-quantum-reference (MQR) laser frequency stabilization system includes a laser system, an MQR system, and a controller. The laser system provides an output beam with an output frequency, and plural feedback beams with respective feedback frequencies. The feedback beams are directed to the MQR system which includes plural references, each including a respective population of quantum particles, e.g., rubidium 87 atoms, with respective resonant frequencies for respective quantum transitions. The degree to which the feedback frequencies match or deviate from the resonance frequencies can be tracked using fluorescence or other electro-magnetic radiation output from the references. The controller can stabilize the laser system output frequency based on plural reference outputs to achieve both short-term and long-term stability, e.g., in the context of an atomic clock.

Chip technology for fabricating ultra-low-noise, high-stability optical devices for use in an optical atomic clock system. The proposed chip technology uses diamond material to form stabilized lasers, frequency references, and passive laser cavity structures. By utilizing the exceptional thermal conductivity of diamond and other optical and dielectric properties, a specific temperature range of operation is proposed that allows significant reduction of the total energy required to generate and maintain an ultra-stable laser. In each configuration, the diamond-based chip is cooled by a cryogenic cooler containing liquid nitrogen.

In a general aspect, a device is disclosed for providing a reference frequency of light. The device includes a housing having a first opening and a second opening. A first optical window covers the first opening and is coupled to the housing by a first ceramic bond that forms a hermetic seal around the first opening. A second optical window covers the second opening and is coupled to the housing by a second ceramic bond that forms a hermetic seal around the second opening. The device also includes an etalon disposed within an evacuated volume enclosed by at least the housing, the first optical window, and the second optical window. The device additionally includes one or more supports suspending the etalon in the evacuated volume. The one or more supports are formed of a material having a thermal conductivity no greater than 5 W/m.Math.K at room temperature.

An apparatus is provided. The apparatus comprises: an optical resonator including a surface; wherein a Bragg grating is formed at least part of the surface of the optical resonator; and wherein the Bragg grating has a Bragg frequency substantially equal to a center frequency of an Nth order Brillouin gain region capable of generating an Nth order Stokes signal.

A method and system for adjusting the profile of a laser wavefront formed by at least a laser beam to a desired laser wavefront profile, the laser beam or beams presenting random phases and intensities, comprises a mixing module, configured to generate, from interference phenomena among the laser beam or beams, a laser field, a second intensity measuring module configured to measure the mixed intensities of the laser field portions, a calculation unit configured to calculate one or several phase correction values of the phase of the laser beam or the phases of laser beams, from the intensities of the laser beams, the mixed intensities and one or several predetermined target phases, and a phase adjustment module configured to apply the phase correction value or values obtained from the calculation unit to the laser beam phases.

An apparatus includes an optical splitter configured to receive an optical signal and to split the input optical signal to provide a first and a second optical signal. The apparatus further includes an interferometer comprising a first arm and a second arm, with the first arm being configured to receive the first optical signal, and the second arm being configured to receive the second optical signal. Notably a portion of the first arm is exposed to a reference gas that attenuates light of a characteristic wavelength. The apparatus further includes an optical coupler configured to receive an output optical signal from the first arm, and an output optical signal from the second arm and to provide a third optical signal; and a photodetector configured to receive the third optical signal, and to provide a photocurrent. The photocurrent increases when the difference between the characteristic wavelength and the wavelength of the optical signals increases. The apparatus also comprises a feedback control circuit configured to change the properties of the laser to be locked until an error signal indicative of the difference between the characteristic wavelength and the wavelength of the laser is substantially zero.

An ultrafast electro-optic laser makes a stabilized comb and includes: a comb generator that produces a frequency comb; a dielectric resonant oscillator; a phase modulator in communication with the dielectric resonant oscillator; an intensity modulator in communication with the phase modulator; an optical tailor in communication with the comb generator and that produces tailored light; a filter cavity in communication with the intensity modulator; a pulse shaper in communication with the filter cavity; a highly nonlinear fiber and compressor in communication with the pulse shaper; an interferometer in communication with the optical tailor and that produces a difference frequency from the tailored light; and an electrical stabilizer in communication with the interferometer and the comb generator and that produces the stabilization signal with a stabilized local oscillator cavity that produces a stabilized local oscillator signal that is converted into the stabilization signal and communicated to the dielectric resonant oscillator.

Disclosed are a quantum-entangled photon-pair light source using a chip-scale atomic ensemble and implementation method thereof. The quantum-entangled photon-pair light source may include an atomic vapor cell configured to generate cesium (Cs) vapor to fill a photon-pair chamber and a processor configured to cause a coupling laser and a pump laser to travel based on the photon-pair chamber and generate a photon pair of a signal and an idler from the atomic vapor cell.

An optical reference cavity includes: a cell that includes: a cylindrical body; end faces; an optical canal having an interior cylindrical geometry; and an exterior surface having an exterior cylindrical geometry; mirrors disposed on the end faces; an aspect ratio that is less than 1; a compression clamp that holds the cell through compression and includes compression platens disposed on the end faces so that the compression platens exert a compressive force to the end faces at a radius from a central axis of the cell so that the cell is compressed by the compression clamp, and a length of the optical canal is unperturbed to first order with a magnitude of the compressive force; and a compression intermediary interposed between the compression platens and end faces, wherein the length of the optical canal is insensitive to vibration coupled to the cell by the compression clamp and compression intermediaries.

A laser system with optical feedback, includes an optical-feedback-sensitive laser which emits, via an output optical fibre, a continuous, frequency-adjustable, propagating, source optical wave, known as the source wave; a resonant optical cavity coupled by means of optical feedback to the laser and configured to generate an intra-cavity wave, one fraction of which returns to the laser in the form of a counter-propagating optical wave; an electro-optic fibre modulator placed on the optical path between the laser and the resonant optical cavity, the electro-optic modulator being configured to generate a phase-shifted source wave by phase-shifting the source wave and, by phase-shifting the counter-propagating optical wave, to generate a phase-shifted counter-propagating wave, known as the feedback wave, which reaches the laser; a phase-control device for generating a control signal for the electro-optic modulator from an error signal representative of the relative phase between the source wave and the feedback wave, such as to cancel the relative phase between the source wave and the feedback wave.