Systems and methods for performing resonator fiber optic gyroscope (RFOG) resonance hopping are described herein. For example, an RFOG includes a fiber optic resonator. The RFOG also includes a plurality of laser sources that each launch a respective laser for propagation within the fiber optic resonator. Further, the RFOG includes a threshold detector that determines when the operation of at least one laser source in the plurality of laser sources exceeds a threshold associated with the operational range of an aspect of the at least one laser source. Additionally, the RFOG includes a hop control logic that adjusts the frequency of at least one laser produced by the at least one laser source one or more resonant modes of the fiber optic resonator such that the aspect of the at least one laser moves away from the threshold towards a nominal value within the operational range.

A tunable narrow-linewidth photo-generated microwave source based on polarization control includes a high-reflectivity fiber grating, a high-gain fiber, a low-reflectivity polarization-maintaining fiber grating, a stress adjusting device, a single-mode semiconductor pump laser, an optical wavelength division multiplexer, a polarization beam splitter, a polarization controller, an optical coupler, and a photoelectric detector. Birefringence distribution in the low-reflectivity polarization-maintaining fiber grating is controlled by adjusting a stress magnitude of the stress adjusting device to the low-reflectivity polarization fiber grating, thereby controlling a laser frequency working in different polarization modes in a resonant cavity, and a tunable narrow-linewidth photo-generated microwave source is generated by a beat-frequency technology using a dual-wavelength narrow-linewidth laser with variable frequency intervals.

The present invention relates to the technical field of optical communications, and relates to an optical amplification method and an amplifier, and in particular, to a self-adaptive wave band amplification method and an amplifier. The present invention consists of a master amplifying unit and a slave amplifying unit, and can autonomously detect the service signal wave band range of an optical transmission line, and according to the detection result, the two amplifying units do not need to perform scheduling or configuration from the level of network management, and perform direct interaction and action from the bottom layer to implement self-adaptive on, off and adjustment in real time. On one hand, power consumption is reduced, and energy is saved; and on the other hand, the performance is optimized, and an optimal optical amplification index is obtained.

An optical device includes first and second 45 Faraday rotators. A 45 polarizer is located between the first and second Faraday rotators such that light in a prescribed polarization state that is incident on the first 45 Faraday rotator traverses the first 45 Faraday rotator as well as the 45 polarizer and the second 45 Faraday rotator. In one implementation the optical device is operable to receive a light beam traveling in a first direction and output a light beam that is in a predetermined polarization state. Likewise, the optical device is operable to receive an unpolarized light beam traveling in a second direction opposite the first direction and outputs a light beam that is in a predetermined polarization state. The polarization state in which the two output beams are arranged may be the same or orthogonal to one another.

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 micro femtosecond laser with reduced radiation and temperature sensitivity is provided. The laser includes a housing with a radiation shield. Optical components that include a micro gain element are received within the housing. An input end of a pump light delivering fiber is positioned outside the housing. An output end of the pump light delivering fiber is positioned within the housing to deliver input beams to the optical components. A light signal generating pump is used to generate the input beams that are communicated to the input end of the pump light delivering fiber. A first end of a hollow core fiber is positioned within the housing to be in optical communication with the optical components. A second end of the hollow core fiber is positioned outside the housing. A partially reflective output coupling mirror is in optical communication with the second end of the hollow core fiber.

Briefly, methods and/or systems, are described for a wavelength-dispersive mode-locked fiber-ring laser, which generates an Airy beam profile for stable optical pulses.

The present invention discloses a transverse mode switchable all-fiber high-order mode Brillouin laser. The laser comprises a narrow linewidth pump laser, an optical amplifier, a 1N optical switch (N2), a fiber mode selection coupler group, a first polarization controller, a fiber circulator, a fiber coupler, a second polarization controller, and a few-mode fiber. Based on the Brillouin nonlinear gain of a few-mode fiber in a ring cavity, the present invention realizes the resonance amplification of a specific order transverse mode in the cavity, and obtains the transverse mode switchable high-order mode laser beam output. The present invention, adopting an all-fiber structure, has the advantages of simple structure, low cost, easy fiber system integration, high stability and narrow linewidth of outputted laser beams, etc., and improves the practicality and reliability of high-order mode lasers.

An example all polarization-maintaining, passively mode-locked linear fiber laser oscillator has a linear cavity. A semiconductor saturable absorber mirror (SESAM) is disposed at one end of the linear cavity. A polarization-maintaining gain fiber is operatively associated with the SESAM in the linear cavity, the gain fiber having normal dispersion. A polarization-maintaining undoped fiber is operatively associated with the SESAM in the linear cavity, the undoped fiber having anomalous dispersion. An output coupler is configured to generate laser light output from the linear cavity.

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.