A Raman fiber laser includes a pump light source, a reflective end mirror, a wavelength division multiplexer, a Raman gain fiber, and an output end mirror. The output end mirror is an ultra-low reflectance fiber Bragg grating. The reflective end mirror is connected to a reflective end of the wavelength division multiplexer. The pump light source is connected to an input end of the wavelength division multiplexer. One end of the Raman gain fiber is connected to a common end of the wavelength division multiplexer, and the other end of the Raman gain fiber is connected to the ultra-low reflectance fiber Bragg grating. The laser of the present invention can reduce loss of laser light at the reflective end mirror, thereby increasing laser light optical conversion efficiency and output power, and simultaneously achieving high time domain stability and extremely low coherence.

A display device includes a laser irradiation device and a control device. The laser irradiation device is configured to irradiate an irradiation point located at a display position in air, with a laser beam having a wavelength equal to or larger than 380 nm and equal to or smaller than 780 nm and produce plasma at the display position. The control device is configured to control intensity of the laser beam emitted from the at least one laser irradiation device so that a relationship between intensity of plasma light emitted from the plasma at the display position and intensity of scattered light produced from the laser beam and scattered by the plasma becomes a predetermined relationship to display a color pixel.

Optical frequency combs are used for a wide range of applications, some of which require precise control of the amplitude and phase of individual comb teeth. A technique is provided for tooth-level optical frequency comb control. A frequency comb may include a plurality of comb teeth that are separated from one another by a comb frequency spacing. This technique includes generating a train of control pulses, each of the control pulses being frequency-locked to a corresponding tooth of an optical frequency comb to be controlled. The tooth-level control of the frequency comb is enabled via stimulated Brillouin scattering using the train of control pulses.

A laser system is provided. The laser system comprises: a seed laser configured to produce a sequence of seed light pulses, wherein the sequence of seed light pulses are produced with variable time intervals in a sweep cycle; a pump laser configured to produce pump light having variable amplitude in the sweep cycle; and a control unit configured to generate a command to the pump laser to synchronize the pump light with the sequence of seed light pulses.

Method and system for a laser welding process employing the use of a single pulsed fiber laser source configured to generate a radiative output with a wavelength spectrum extending from about 1.8 microns to about 2.6 microns. In a specific case, the laser output from the single pulsed fiber laser source is focused onto the interface of the two pieces of materials at least one of which includes any of glasses, inorganic crystals, and semiconductors.

An optical fiber fuse protection device includes an upstream optical fiber disposed on an upstream side, a downstream optical fiber disposed on a downstream side, and a wall interposed between a part of the upstream optical fiber and a part of the downstream optical fiber. The downstream optical fiber is fusion-spliced to the upstream optical fiber and is made of a single optical fiber or a plurality of optical fibers fusion-spliced to each other.

An optical amplifier assembly and a detection method capable of dynamically performing optical time-domain reflection detection. The detection method comprises obtaining signal light intensity detection signals from a first and second photodetectors and sending a control signal to an L-band Raman pump when the signal light intensity in the second photodetector is lower than a first preset threshold, so that the L-band Raman pump enters into an optical time-domain reflection detection mode; sending a control signal to the L-band Raman pump when the signal light intensity in the second photodetector is greater than or equal the first preset threshold, so that the L-band Raman pump enters into an L-Band Raman optical fiber amplifier operation mode.

A fixed input current is provided to a pump laser of an optical pumping block. Further, a first tuning temperature is provided to the pump laser while providing the fixed input current. The first tuning temperature is based on a target band of a pumping beam and causes the pump laser to generate a light beam having a first frequency band that is dictated by the first tuning temperature and the fixed input current. Further, a second tuning temperature is provided to a temperature dependent optical reflector configured to receive the light beam. The second tuning temperature is based on the target band of the pumping beam and causes the optical reflector to reflect light of the light beam that is within a second frequency band that corresponds to the target frequency band. The reflected light beam is emitted into a transmission optical medium configured to carry an optical signal.

The present invention is to provide a backscattered light amplification device, an optical pulse test apparatus, a backscattered light amplification method, and an optical pulse test method for amplifying a desired propagation mode of Rayleigh backscattered light with a desired gain by stimulated Raman scattering in a fiber under test having the plurality of propagation modes. The backscattered light amplification device according to the present invention is configured to control individually power, incident timing, and pulse width of a pump pulse for each propagation mode when the pump pulse is incident in a plurality of propagation modes after the probe pulse is input to the fiber under test in any propagation mode.

A method for reducing or eliminating bias instability in a SBS laser gyroscope comprises introducing a first pump signal propagating in a CW direction, and a second pump signal propagating in a CCW direction in a resonator; generating a CCW first-order SBS signal and a CW first-order SBS signal in the resonator; increasing a power level of the first pump signal above a threshold level such that the CW first-order SBS signal generates a CCW second-order SBS signal; and increasing a power level of the second pump signal above the threshold level such that the CCW first-order SBS signal generates a CW second-order SBS signal. Above the threshold level, an intensity fluctuation of the first-order SBS signals disappear and their DC power are clamped at substantially the same power level. A Kerr effect bias instability of the SBS laser gyroscope is reduced or eliminated by the clamped first-order SBS signals.