Disclosed is a multimode interference effect-based wide tunable single-frequency optical fiber laser device. The laser device comprises a high-reflectivity chirped optical fiber grating, a high-gain optical fiber, a low-reflectivity chirped optical fiber grating, a pump source, an optical circulator, an optical fiber etalon and an SMS optical fiber structure apparatus. The high-reflectivity chirped optical fiber grating, the high-gain optical fiber and the low-reflectivity chirped optical fiber grating are connected in sequence to form a short linear resonant cavity; the optical circulator, the optical fiber etalon and the SMS optical fiber structure apparatus form a ring cavity, a stress loader is fixed onto the SMS optical fiber structure apparatus, and a transmitting wavelength of the SMS optical fiber structure apparatus is changed and tunable filtering by the SMS optical fiber structure apparatus is realized by loading stress to the SMS optical fiber structure apparatus.

A system and method for generating ultra-short pulses intended to be inserted into a ring laser with a regulator of a pulsed signal of a certain intensity, the system includes an optical attenuator that allows the intensity of the pulsed signal to be adjusted at the input of an optical guide section, and a distributed amplification device inserted in the optical guide that make it possible to manage the power of the signal therein, so that it propagates as solitons or as self-similar pulses without suffering unwanted distortions despite the increase in the length of the laser cavity, increasing the power of the pulsed signal and making it possible to exceed the usual power limits of this type of laser.

A tunable millimeter-wave signal oscillator includes two phase coherent optical oscillators, a fiber-ring cavity configured to generate two Stokes waves, and a photosensitive element converting the frequency difference of two optical oscillator into a millimeter-wave radiation. A chip-scale form factor millimeter-wave oscillator includes two continuous wave lasers, a plurality of micro-optical-resonators, an optical frequency division mechanism, two optical tunable bandpass filters, and a photosensitive element converting the pulse train of a frequency comb into a millimeter-wave radiation. A millimeter-wave phase noise analyzer includes an optical interferometer, two photosensitive elements, and a fundamental millimeter-wave frequency mixer. A millimeter-wave frequency counter includes an electro-optic optical frequency comb generator, a microwave voltage controlled oscillator, and an optoelectronic phase locked loop. A millimeter-wave electrical spectrum analyzer includes a millimeter-wave phase noise analyzer, a millimeter-wave amplitude detector, a millimeter-wave frequency counter, and a data processing unit.

An optical assembly provides dispersion control, modelocking, spectral filtering, and/or the like in a laser cavity. For example, the optical assembly may comprise a diffraction grating pair arranged to temporally and spatially disperse a beam on a forward pass through the optical assembly, a reflective device at an end of the optical assembly, and a focusing optic arranged to create a beam waist at the reflective device. The beam waist created at the reflective device may cause the beam to be inverted on a reverse pass through the optical assembly, and a temporal dispersion and a spatial dispersion of the beam may be doubled on the reverse pass through the optical assembly to form a temporally and spatially dispersed output from the optical assembly.

A laser apparatus, a measurement apparatus, and a measurement method are provided in which the laser apparatus outputs a frequency-modulated laser beam with a plurality of modes and includes: an optical cavity that has a gain medium for amplifying a light to be input, and an optical SSB modulator for shifting a frequency of the light amplified by the gain medium: and a control part that controls the optical SSB modulator to shift a frequency of a light to be input to the optical SSB modulator.

A laser system and method. In one example, the laser system includes an optical pulse stretcher configured to stretch pulse durations of an input train of input pulses to produce a train of stretched laser pulses, a pulse replicator module configured to increase a pulse repetition rate of the train of stretched laser pulses to produce a modified pulse train of laser light, a fiber power amplifier configured to amplify the modified pulse train to produce amplified laser pulses, and a pulse compressor that temporally compresses the amplified laser pulses to produce amplified and compressed laser pulses. The system may further include a nonlinear frequency conversion stage comprising at least one nonlinear crystal.

This invention disclosed a system and method for characteristics measurement of electromagnetic signals. The measurement system comprises a multi-repetition-rate pulsed light source, a frequency mixer for electrical signal and optical signal, and a data acquisition and processing device. The measurement system accurately determines the characteristic information of the signal to be measured, such as frequency, phase, intensity, and their variations, by measuring the low frequency mixed signal generated by the multi-repetition-rate pulsed light source and the signal to be measured in the frequency mixer. This system has the advantages of simple structure, high measurement accuracy, low cost and large measurable frequency range. The system can be applied to the measurement of various electromagnetic signals, covering the spectral range from microwave, millimeter wave, to terahertz and even light wave.

An amplified spontaneous emission (ASE) light source and a method for using the ASE light source are provided. The ASE light source may include a seed stage light source for providing a light beam to be amplified. The apparatus may include a tunable element coupled to the seed stage light source configured for filtering a portion of the light beam from the seed stage light source. The apparatus may include a loopback circuit coupled to the tunable element, the loopback circuit comprising a booster stage element for amplifying light from the tunable element.

Typically, quantum systems are very sensitive to environmental fluctuations, and diagnosing errors via measurements causes unavoidable perturbations. Here, an in situ frequency-locking technique monitors and corrects frequency variations in single-photon sources based on resonators. By using the classical laser fields used for photon generation as probes to diagnose variations in the resonator frequency, the system applies feedback control to correct photon frequency errors in parallel to the optical quantum computation without disturbing the physical qubit. Our technique can be implemented on a silicon photonic device and with sub 1 pm frequency stabilization in the presence of applied environmental noise, corresponding to a fractional frequency drift of <1% of a photon linewidth. These methods can be used for feedback-controlled quantum state engineering. By distributing a single local oscillator across a one or more chips, our approach enables frequency locking of many single photon sources for large-scale photonic quantum technologies.

The present disclosure provides a waveguide integrated optical modulator, which is made of a bismuth film, an antimony film, or a tellurium film. A thickness of the bismuth film, the antimony film, or the tellurium film is between 10 nm and 200 nm, and the bismuth film, the antimony film, or the tellurium film is produced by physical vapor deposition method. The waveguide integrated optical modulator can directly add the symmetrical electrode on the surface of the bismuth film, the antimony film, or the tellurium film, and apply an external bias voltage of different amplitudes to the bismuth film, the antimony film, or the tellurium film by adjusting the power source. Thus, the waveguide integrated optical modulator can actively control the nonlinear optical characteristics of the saturable absorber by changing the magnitude of the external voltage, and further actively modulate the laser characteristics of the pulse.