4 results about "Nonlinear phase shift" patented technology

The application discloses a GHz high-repetition 9-shaped cavity mode-locked fiber laser and a starting method thereof, and particularly relates to the technical field of ultrafast laser, a nonlinear amplification ring mirror, and an auxiliary starting light path arranged outside the nonlinear amplification ring mirror and used in a mode-locked starting stage; the auxiliary starting light path comprises a second reflector, a focusing lens and a semiconductor saturable absorber mirror. The GHz high-repetition 9-shaped cavity mode-locked fiber laser and the starting method thereof have the advantages that by introducing an external and separable auxiliary starting light path, seed light with high peak power is formed in the starting stage, the problem that a nonlinear phase shift difference of an extremely short cavity length is insufficient to cause mode-locked difficulty is effectively solved, stable mode locking of GHz-level repetition frequency pulse output is realized, in a steady-state operation stage, the laser completely relies on the nonlinear amplification ring mirror with low noise and high stability to realize mode locking, and high-stability, low-noise and repetition frequency ≥1GHz pulse output is obtained.

The application relates to the technical field of lasers and discloses a self-starting 9-shaped cavity fiber laser with an adjustable feedback loop and a use method, which comprises a nonlinear amplification ring mirror and a linear arm, and a third coupler is arranged between the nonlinear amplification ring mirror and the linear arm; the nonlinear amplification ring mirror comprises a gain optical fiber, a polarization-maintaining wavelength division multiplexer and a phase shifter, the gain optical fiber, the polarization-maintaining wavelength division multiplexer and the phase shifter are sequentially and closely connected, and the polarization-maintaining wavelength division multiplexer is connected with a pump source; a feedback unit is arranged on the nonlinear amplification ring mirror, and the feedback unit is in communication with the gain optical fiber and the polarization-maintaining wavelength division multiplexer at two ends, respectively; and the light output from the rear end of the gain optical fiber is fed back to the gain optical fiber through the feedback unit to form a feedback loop. The application enhances the noise energy in the cavity by constructing a closed-loop feedback loop, reduces the mode-locking threshold and the starting time, dynamically adjusts the gain optical fiber amplification gain, stably controls the nonlinear phase shift accumulation, avoids an external complex system, and realizes the all-fiber low-to-high efficient design.

The embodiment of the present application provides a kind of adjustable all-optical shaper, adjustable all-optical shaper parameter determination method and device.The shaper includes: MZI shaping module, first directional coupler and second directional coupler;MZI shaping module includes: upper arm and lower arm;The output end of first directional coupler is connected with the input end of MZI shaping module respectively;Upper arm includes: nonlinear optical fiber and adjustable optical phase shifter, for the nonlinear phase shift of one of the two optical signals in nonlinear optical fiber, and the phase shift of one optical signal after nonlinear phase shift is carried out by adjustable optical phase shifter with preset phase shift value;Lower arm includes: linear optical fiber, for the linear phase shift of one of the two optical signals in linear optical fiber;The input end of second directional coupler is connected with the upper arm and the lower arm of MZI shaping module.

The application belongs to the technical field of lasers, and specifically provides a high-repetition-frequency 9-shaped cavity fiber laser, which comprises a wavelength division multiplexing coupler, a laser output assembly and a non-reciprocal phase shift component for generating a nonlinear phase shift; the non-reciprocal phase shift component comprises a phase shifter and a polarization maintaining fiber; the phase shifter is located on an outgoing light path of the wavelength division multiplexing coupler; an input end of the polarization maintaining fiber is located on an outgoing light path of the phase shifter, and an output end of the polarization maintaining fiber is connected with the wavelength division multiplexing coupler; the laser output assembly is connected with the wavelength division multiplexing coupler; the laser output assembly is used for reflecting part of input laser of the wavelength division multiplexing coupler back to the wavelength division multiplexing coupler and outputting the other part. The high-repetition-frequency 9-shaped cavity fiber laser can generate sufficient nonlinear phase shift for mode locking without a long passive optical fiber by integrating the polarization maintaining fiber region in the non-reciprocal phase shift section, and then the cavity length is shortened and the repetition frequency is improved, so that the fiber laser can output laser with high repetition frequency.