6 results about "Nonlinear polarization" patented technology

The application discloses an interference filter type multi-wavelength erbium-doped fiber laser based on optical path difference regulation, relates to the technical field of a ring-shaped tunable multi-wavelength erbium-doped fiber laser, and comprises a pump source, a wavelength division multiplexer, an erbium-doped fiber, an isolator, a first optical fiber coupler, a three-paddle polarization controller, a polarizer, a Mach-Zehnder interferometer filter containing an adjustable delay line, a black phosphorus saturable absorber and an extrusion type polarization controller which constitute a ring cavity. By connecting a 0-6.6 cm continuous adjustable delay line to one arm, the optical path difference of the filter two arms is accurately regulated, and continuous precise tuning of wavelength spacing of 0.3 nm to 1.54 nm is realized; meanwhile, by combining the nonlinear polarization rotation effect and the hybrid mode-locking mechanism of the few-layer black phosphorus, the mode-locking threshold is significantly reduced, and the long-term stability of the pulse is improved. The laser can realize stable emission of up to six wavelengths at the same time, the wavelength drift is less than 0.75 nm, and the power fluctuation is less than 7.0 dB.

The application provides a polarization-dependent device and an optical fiber laser, wherein self-made polyester transparent adhesive is used as a transmission tool, tantalum palladium sulfide is accurately placed in the center of the end face of an optical fiber jumper under a microscope, and the tantalum palladium sulfide is connected with another optical fiber jumper by using an optical fiber sleeve to form the polarization-dependent device. The tantalum palladium sulfide has excellent nonlinear polarization optical response, under the condition that the input pump power is constant, the polarization-dependent device based on the tantalum palladium sulfide can realize stable soliton and noise-like dual-mode controllable switching in a single superfast optical fiber laser. In a single superfast optical fiber laser system, the controllable stable switching of different superfast laser pulse modes has great expansion application potential. The polarization-dependent device based on the tantalum palladium sulfide in the application has simple structure, simple preparation and low cost, and has good nonlinear optical performance and long-term working stability.

The application discloses a near-transform limit nanosecond pulse mode-locked fiber laser with periodic bifurcation and a producing method. The laser is a fiber ring cavity which comprises a wavelength division multiplexer, an erbium-doped fiber, a first polarization controller, a polarization detector, a dispersion control unit, an output coupler, a fiber isolator and a second polarization controller which are connected in sequence in a closed loop. The method comprises the following steps: coupling pump continuous light into the laser through the wavelength division multiplexer; absorbing the pump continuous light by the erbium-doped fiber and radiating gain pulses in a long-wave band; oscillating the generated pulses in the fiber laser cavity; through the cooperation of the first polarization controller, the polarization detector and the second polarization controller, generating equivalent saturated absorption effect by using the nonlinear polarization rotation generated when the gain pulses propagate in the fiber, and realizing pulse mode-locking; and making the fiber laser work in an abnormal dispersion region so that the generated pulses satisfy the soliton area theorem and near-transform limit pulses are generated. The application can realize nanosecond pulse periodic bifurcation output of a short-cavity fiber laser.

This application provides an intelligent mode-locked fiber laser based on nonlinear polarization interference and its control method, belonging to the field of fiber laser and intelligent control technology. The application includes: scanning a waveplate, setting the angle corresponding to the maximum power as the mechanical zero point, and establishing a correspondence between angle and power; using the mechanical zero point as a reference and the correspondence between angle and power, scanning the waveplate with a first-step scanning length, marking states that meet the spectral width condition and exhibit a comb-like structure as mode-locking candidate points; using the mode-locking candidate points as the center, scanning with a second-step scanning length, determining mode-locking when the spectral bandwidth reaches a threshold and the power standard deviation is less than a stability threshold, recording the current power standard deviation as the reference fluctuation value, and recording the corresponding angle as the target mode-locked operating point; monitoring output parameters, calculating the power standard deviation and comparing it with the reference fluctuation value, and triggering a local search to restore mode-locking when the deviation exceeds the allowable range. This application can achieve automatic tuning of the intracavity polarization state and phase shift.