Dissipative soliton evolution in passively mode-locked fiber lasers with large net-normal-dispersion and high nonlinearity is investigated numerically and confirmed experimentally. I have proposed a theoretical model including the nonlinear polarization evolution and spectral filtering effect. This model successfully predicts the pulse behaviors of the proposed laser, such as the multi-soliton evolution, quasi-rectangle-spectrum profile, trapezoid-spectrum profile, and unstable state. Numerical results show that, in contrast to the typical net- or all-normal-dispersion fiber lasers with the slight variation of the pulse breathing, the breathing ratios of the pulse duration and spectral width of our laser are more than three and two during the intra-cavity propagation, respectively. The nonlinear polarization rotation mechanism together with spectral filtering effect plays the key roles on the pulse evolution. The experimental observations confirm the theoretical predictions.

Numerical and experimental investigation of dissipative solitons in passively mode-locked fiber lasers with large net-normal-dispersion and high nonlinearity

Lasers and Coherent Light Sources

Summary form only given. We demonstrate for the first time, we believe, a broadband low-finesse antiresonant Fabry-Perot saturable absorber (A-FPSA) that starts Kerr lens mode-locking (KLM) of a Ti:sapphire laser and supports 10-fs pulses.

Broadband saturable absorber for 10-fs pulse generation

Generation, optimization, and application of ultrashort femtosecond pulse in mode-locked fiber lasers

A diode-pumped passively Q-switched mode-locked (QML) Nd:GdVO4 laser with a low temperature GaAs (LT-GaAs) saturable absorber is presented. The maximal Q-switched mode-locked average output power was 798 mW with the Q-switched envelop having a repetition rate of 125 kHz. The mode-locked pulse trains inside the Q-switched pulse envelope had a repetition rate of similar to 750 MHz. The laser properties of the operational parameters on the pump power were also investigated experimentally.

https://iopscience.iop.org/article/10.1002/lapl.200610062/pdf

Experiments of a diode-pumped Nd:GdVO4/LT-GaAs Q-switched and mode-locked laser

Passive mode-locking of a pulsed Nd:YAG laser using a Cr4+:YAG saturable absorber was realized for the first time in a nearly critical stable resonator containing an antiresonant ring structure. The output energy and pulse duration are 13.5 mJ and 180 ps, respectively. The recovery time and saturable intensity for excited-state absorption of Cr4+:YAG under the action of strong laser pulses were calculated from rate equations.

Investigation of Cr4+:YAG passive mode-locking in a pulsed Nd:YAG laser

It Is reported that the supercontinuum spectrum can be generated in holey microstructure fibers by femtosecond laser pulses with a 800nm center wavelength. Broadband continua extending from 440 to 890nm are generated in holey microstructure fibers. Based on the theory of scalar approximation, the effective refractive index of the cladding and effective area for the fundamental space-filling mode and chromatic dispersion of fibers are calculated. It is found that the holey microstructure fibers have specifically the ability of controlling dispersion and waveguide property. The mechanism of supercontinuum generation in holey microstructure fibers is explicated preliminarily. The theoretic analysis is in good accodance with the experimental result. It is, considered that supercontinuum broadband spectrum can be generated in holey microstructure fibers even if their cladding constitutes of random gas-line.

Supercontinuum generation in holey microstructure fibers by femtosecond laser pulses

The photo-induced insulator-metal transition for silicon-based VO 2 nanofilm is studied by THz time-domain spectroscopy (THz-TDS). Obvious variations of THz ray transmittance are observed before and after the CW laser beam exciting, and the conductivity of metallic-phased VO 2 film in the THz region is calculated in the thin film approximation. According to the measured results, the metallic-phased VO 2 film is characterized equivalently with Drude’s model, and complex conductivity, dielectric function and refractive index are acquired by the model. As an examination on the equivalent Drude model, numerical simulation based on the finite integral method in time domain is carried out. The results show that they are in good agreement with the experimental results. This work provides a reference for the study on phase transition of VO 2 nanofilm and its application in the THz region.

Photo-induced insulator-metal transition of silicon-based VO 2 nanofilm by THz time domain spectroscopy

A compact and highly stable high pulse energy passively mode-locked fiber laser is presented. A segment of Yb 3+ -doped double-clad large-mode-area fiber with extremely low nonlinearity is developed as the active medium. The self-starting mode-locked operation is achieved by the cooperation of nonlinear polarization evolution and semiconductor saturable-absorber mirror. The fiber laser generates laser pulses with the average power of 160mW at the repetition rate of 55.9MHz (corresponding to pulse energy of 3nJ), and the pulse duration is 10.6ps.

A mode-locked Yb 3+ -doped double-clad large-mode-area fiber laser

We propose a novel technique for generating intense few to mono-cycle femtosecond pulses. The simulation demonstrate that for the temperature difference of 300K, the spectrum of the output pulses is increased by 67% and the transform limited pulse width is reduced almost by half, compared with those obtained with hollow fibres in uniform temperature.

Wang Qing-Yue

Papers

Investigation of Cr4+:YAG passive mode-locking in a pulsed Nd:YAG laser

Supercontinuum generation in holey microstructure fibers by femtosecond laser pulses

Photo-induced insulator-metal transition of silicon-based VO 2 nanofilm by THz time domain spectroscopy

A mode-locked Yb 3+ -doped double-clad large-mode-area fiber laser

Simulation of Femtosecond Pulse Propagation through Hollow Fibre Filled with Noble Gases of Gradient Temperature