A laser system comprising two phase-locked solid-state laser sources is described. The laser system can be phase-locked at a predetermined offset between the operating frequencies of the lasers. This is achieved with high precision while exhibiting both low noise and high agility around the predetermined offset frequency. A pulse generator can be employed to generate a series of optical pulses from the laser system, the number, duration and shape of which can all be selected by a user. A phase-lock feedback loop provides a means for predetermined frequency chirps and phase shifts to be introduced throughout a sequence of generated pulses. The laser system can be made highly automated. The above features render the laser system ideally suited for use within coherent control two-state quantum systems, for example atomic interferometry, gyroscopes, precision gravimeters gravity gradiometers and quantum information processing and in particular the generation and control of quantum bits.

A tunable laser system includes a tunable laser to be scanned over a range of frequencies and an interferometer having a plurality of interferometer outputs. At least two interferometer outputs of the plurality of interferometer outputs have a phase difference. A wavelength reference has a spectral feature within the range of frequencies, and the spectral feature does not change in an expected operating environment of the tunable laser. Processing circuitry uses the spectral feature and the plurality of interferometer outputs to produce an absolute measurement of a wavelength of the tunable laser and controls the tunable laser based on a comparison of the absolute measurement of the wavelength of the tunable laser with a setpoint wavelength.

A laser device includes an excitation light source, a resonator which receives excitation light from the excitation light source and generates laser light, an absorption cell to which the laser light is emitted, a light converter which converts the laser light passing through the absorption cell to a light output signal, a third order differential lock-in amplifier which generates a third order differential signal of the light output signal, and a controller. When a predetermined waveform of the third order differential signal is detected, the controller includes a return controller that determines a return direction of a resonator length based on the predetermined waveform and a resonator length controller that changes the resonator length to the return direction.

A tunable laser system includes a tunable laser to be scanned over a range of frequencies and an interferometer having a plurality of interferometer outputs. At least two interferometer outputs of the plurality of interferometer outputs have a phase difference. A wavelength reference has a spectral feature within the range of frequencies, and the spectral feature does not change in an expected operating environment of the tunable laser. Processing circuitry uses the spectral feature and the plurality of interferometer outputs to produce an absolute measurement of a wavelength of the tunable laser and controls the tunable laser based on a comparison of the absolute measurement of the wavelength of the tunable laser with a setpoint wavelength.

A method for the servo control of an optical device includes a cavity exhibiting resonance around a center frequency ?.sub.c, a laser and a phase modulator, the method being designed to servo-control the cavity to the laser or vice versa and to compensate for an amplitude modulation introduced by the phase modulator, the method comprising, inter alia, the following steps: A. varying a difference ?? between the optical frequency of the laser radiation and the center frequency, such that the optical frequency scans the resonance, the difference being controlled by a parameter of an element of the device, and for each difference ??.sub.i i. modulating, at a modulation frequency ?.sub.mod, a phase of the laser radiation, through a modulation phase ?.sub.mod, with the phase modulator, ii. injecting the phase-modulated radiation into the cavity, iii. using a photodiode to detect radiation reflected or transmitted by the cavity and generating an electrical signal (St, Sr) representative of the intensity of the detected radiation, iv. demodulating the electrical signal at the modulation frequency ?.sub.mod by synchronously generating a first demodulated signal and a second demodulated signal representative of the demodulated electrical signal, respectively at a first demodulation phase ?.sub.dem,1 and at a second modulation phase ?.sub.dem,2?.sub.dem,2??.sub.dem,1k, where k?[0; 2?] is different from the first phase, and by filtering the first and the second signal so as to retain only a DC component of the first demodulated signal V?.sub.1, called error signal 1, and of the second demodulated signal V?.sub.2, called error signal 2.

The disclosure relates in some aspects to a two-point locking system for stabilizing a frequency comb oscillator using at least two optical transitions of the same atomic/molecular sample. In an example, an optical reference sample is provided that is characterized by two or more optical transitions. A coherent light source provides polychromatic coherent light (such as an optical frequency comb). The beams of light, occupying the same spatial mode volume or separated in space, and having frequencies in the vicinity of the optical transitions of the reference sample, interrogate the resonances of the reference sample. Interrogation signals obtained using phase/frequency/amplitude spectroscopy or other spectroscopy techniques are then used to stabilize the frequency harmonics of the light. If the harmonics belong to the same coherent frequency comb, the entire comb becomes stabilized using this procedure. In an illustrative example, a stable atomic optical clock is provided using these techniques.

A laser device includes an excitation light source, a resonator which receives excitation light from the excitation light source and generates laser light, an absorption cell to which the laser light is emitted, a light converter which converts the laser light passing through the absorption cell to a light output signal, a third order differential lock-in amplifier which generates a third order differential signal of the light output signal, and a controller. When a predetermined waveform of the third order differential signal is detected, the controller includes a return controller that determines a return direction of a resonator length based on the predetermined waveform and a resonator length controller that changes the resonator length to the return direction.

A current control device supplies a current to a semiconductor laser in order to output laser light to the semiconductor laser, and includes a current commander and a supplier. The current commander outputs a command value corresponding to a current value by increasing the command value with a lapse of time until reaching a target command value corresponding to a current value for outputting the laser light with a predetermined strength. The supplier supplies a current with a size corresponding to the command value output by the current commander to the semiconductor laser.

The present invention relates to a device and a method for performing overall frequency stabilization of a femtosecond laser optical comb by using optical modes directly extracted from the optical comb, and more particularly, to a device and a method for performing overall frequency stabilization of a femtosecond laser optical comb by using optical modes directly extracted from the optical comb capable of stabilizing an overall range of frequencies of the femtosecond laser optical comb by using optical modes directly extracted from the optical comb and generating a cw laser and pulse having an excellent frequency stability and linewidth from the stabilized optical comb.

In some embodiments, a system includes a laser that generates an optical signal and a resonator that receives the optical signal. The resonator includes an optical resonator cavity comprising a first and second end, wherein the optical signal propagates at a resonant frequency; a first optical anti-resonator terminating the first end and having a first stopband; and a second optical anti-resonator terminating the second end and having a second stopband. The system includes a detector that generates an electrical signal from a modified resonator output of the resonator; and Pound-Drever-Hall servo circuitry configured to generate control signals for controlling a frequency of the optical signal generated by the laser or phase modulation devices attached to the optical resonator cavity or the first or second optical anti-resonator, wherein each phase modulation changes a length of at least one of the optical resonator cavity or the first or second optical anti-resonator.