H01S3/1118

All-fiber bidirectional synchronously pumped ultrafast ring oscillator for precision sensing

A pumped optical ring laser sensor such as a gyroscope includes a pulsed laser source to generate optical pump pulses and a synchronously pumped ring laser. The ring laser is optically pumped by first optical pump pulses from the pulsed laser source that are directed in a clock-wise (CW) direction through the ring laser and by second optical pump pulses from the pulsed laser source that are directed in a counter-clock wise (CCW) direction through the ring laser. The ring laser has an optical resonator that includes a gain medium for producing CW and CCW frequency-shifted pulses from the first and second optical pump pulses. The ring laser further includes a port for receiving the first and second pump pulses and for extracting the CW and CCW frequency-shifted pulses from the ring laser such that the frequency-shifted pulses overlap in time after being extracted to generate a beatnote.

PASSIVELY Q-SWITCHED SOLID-STATE LASER WITH COMPRESSED PULSE DURATION
20200251875 · 2020-08-06 · ·

A passively Q-switched solid-state laser includes a resonator (1) with an active laser material (2) and a decoupling end mirror (6) for decoupling laser pulses that have a pulse duration of less than 1 ns from the resonator (1), an optical fiber (13), into which the laser pulses decoupled from the decoupling end mirror (6) are injected, and a chirped volume Bragg grating (17), at which the laser pulses are reflected after they have passed through the optical fiber (13) for shortening the pulse duration. The pulse duration after the reflection on the chirped volume Bragg grating (17) is less than 30 ps. The active laser material (2) is Nd:YAG and a saturable absorber (3) that is formed from Cr:YAG and has a transmission in the unsaturated state of less than 50% is also arranged in the resonator. The length (a) of the resonator (1) is from 1 mm to 10 mm and the laser pulses decoupled at the decoupling end mirror (6) have a pulse energy from 1 J to 200 J.

A FIBER LASER SYSTEM BASED ON SOLITONIC PASSIVE MODE-LOCKING

A fiber laser system based in solitonic passive mode-locking, including a laser diode to emit and deliver an optical signal of a first wavelength; a single-fiber laser cavity including a dichroic mirror, a SESAM and a polarization maintaining highly-doped active fiber, to receive the emitted signal and to emit a pulsed optical signal of a second wavelength, generating laser light in the form of mode-locked ultrashort pulses; a unit coupling the laser diode to the single-fiber laser cavity; and an isolator device protecting the cavity from back reflections. The solitonic mode-locked ultrashort pulses are comprised in a range of 100 fs<10 ps with repetition rates of hundreds MHz to tens of GHz.

FEMTOSECOND MODE-LOCKED LASER WITH REDUCED RADIATION AND TEMPERATURE SENSITIVITY

In an example, a mode-locked laser includes a resonator cavity having a saturable absorber, a hollow core fiber coupled to the saturable absorber, and an optical amplifier optically coupled between the hollow core fiber and an output coupler. The mode-locked laser further includes a first pump laser and a wavelength division multiplexer coupled to the first pump laser. The wavelength division multiplexer is configured to couple light from the first pump laser into the resonator cavity to pump the optical amplifier. The mode-locked laser is configured to generate a pulse waveform at a repetition rate of approximately 100 MHz to 200 MHz.

LASER DEVICE

A laser device for outputting filtered light pulses for inducing coherent Raman scattering in a sample. The laser device comprises a first optical cavity comprising a first gain medium; and a second optical cavity comprising a second gain medium different to the first gain medium. The first gain medium and the second gain medium are each excitable by a pump light source to generate light at respective different ranges of wavelengths. A synchronizer is optically coupled to both the first optical cavity and the second optical cavity. The synchronizer is configured to synchronize and mode-lock light from the first optical cavity and the second optical cavity. The laser device also includes a first optical filter and a second optical filter. The first optical filter and the second optical filter are configured to filter the light from the first optical cavity and the second optical cavity respectively in order to output first filtered light pulses at a first predetermined range of wavelengths and second filtered light pulses at a second predetermined range of wavelengths.

Generation of Ultrashort Laser Pulses at Wavelengths
20200194959 · 2020-06-18 · ·

A method for generating pulsed laser radiation in the spectral range from 860 nm to 1000 nm is disclosed, including the steps of generating pulsed laser radiation in the spectral range from 1500 nm to 1600 nm, preferably at a wavelength of 1560 nm; shifting the wavelength of the pulsed laser radiation to a longer wavelength of at least 1720 nm, and preferably to 1840 nm; amplifying the wavelength-shifted pulsed laser radiation in a Thulium-doped gain medium so that the Thulium-doped gain medium is pumped in an in-band pumping scheme; and frequency-doubling the amplified wavelength-shifted pulsed laser radiation. A laser system suitable for practicing the method is also disclosed.

Network system

A network system comprises a plurality of nodes and a plurality of optical amplifiers. A first node comprises a first transmitter configured to send a wavelength-division-multiplexed optical signal and a first receiver configured to receive a wavelength-division-multiplexed optical signal, and the second node comprises a second transmitter configured to send a wavelength-division-multiplexed optical signal and a second receiver configured to receive a wavelength-division-multiplexed optical signal. The first and second transmitters are optically connected to an input of the first optical amplifier and an input of the second optical amplifier, respectively, and the first and second receivers are optically connected to an output of the first optical amplifier and an output of the second optical amplifier, respectively. The receivers each comprise a photoreceiver and a reception circuit. The photoreceiver is electrically connected, by flip chip connection, to a reception circuit. A reception circuit is configured not to comprise a transimpedance amplifier.

System and Method for Measuring Time-Frequency Characteristic of High-Frequency Electromagnetic Signal
20200124650 · 2020-04-23 · ·

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.

High-Power Mode-Locked Laser System and Methods of Use

A high-power mode-locked laser system is disclosed herein which includes at least one pump source, at least one laser cavity formed by at least one high reflector and at least one output coupler, and at least one ytterbium-doped optical crystal positioned within the laser cavity in communication with the pump source, the ytterbium-doped optical crystal configured to output at least one output signal of at least 20 W, having a pulse width of 200 fs or less, and a repetition rate of at least 40 MHz.

WAVEGUIDE INTEGRATED OPTICAL MODULATOR, PULSED OPTICAL FREQUENCY COMB AND MODE-LOCKED FIBER LASER
20200106238 · 2020-04-02 ·

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.