Vyacheslav V. Grebenyukov

Ultra-short pulse generation in the hybridly mode-locked erbium-doped all-fiber ring laser with a distributed polarizer

We report for the first time to the best of our knowledge on the ultra-short pulse (USP) generation in the dispersion-managed erbium-doped all-fiber ring laser hybridly mode-locked with boron nitride-doped single-walled carbon nanotubes in the co-action with a nonlinear polarization evolution in the ring cavity with a distributed polarizer. Stable 92.6 fs dechirped pulses were obtained via precise polarization state adjustment at a central wavelength of 1560 nm with 11.2 mW average output power, corresponding to the 2.9 kW maximum peak power. We have also observed the laser switching from a USP generation regime to a chirped pulse one with a corresponding pulse-width of 7.1 ps at the same intracavity dispersion.

Performance peculiarities of carbon-nanotube-based thin-film saturable absorbers for erbium fiber laser mode-locking

We have studied the saturation behavior of single-walled carbon-nanotube-based saturable absorbers (SWCNT-SAs) at different temperatures and SWCNT concentrations in the polymer matrix and tried to relate it to the mode-locked erbium-doped fiber laser performance. It has been observed that a modulation depth of SWCNT-SA transmission which we relate to the ground state recovery time monotonically decreases upon temperature growth. Comparing laser performance with different SWCNT-SAs, we suppose that the defects in the CNT lattice promote recovery acceleration resulting in shorter pulse generation as obtained for boron-nitride-doped SWCNTs. Moreover, for the first time, to the best of our knowledge, we have observed and studied the long-term relaxation of SWCNT-SA saturated transmission exhibiting temperature-dependent behavior.

Hybrid mode-locked erbium-doped all-fiber soliton laser with a distributed polarizer

A soliton-type erbium-doped all-fiber ring laser hybrid mode-locked with a co-action of arc-discharge single-walled carbon nanotubes (SWCNTs) and nonlinear polarization evolution (NPE) is demonstrated. For the first time, to the best of our knowledge, boron nitride-doped SWCNTs were used as a saturable absorber for passive mode-locking initiation. Moreover, the NPE was introduced through the implementation of the short-segment polarizing fiber. Owing to the NPE action in the laser cavity, significant pulse length shortening as well as pulse stability improvement were observed as compared with a SWCNTs-only mode-locked laser. The shortest achieved pulse width of near transform-limited solitons was 222 fs at the output average power of 9.1 mW and 45.5 MHz repetition frequency, corresponding to the 0.17 nJ pulse energy.

Generation regimes of bidirectional hybridly mode-locked ultrashort pulse erbium-doped all-fiber ring laser with a distributed polarizer

We report on the stable picosecond and femtosecond pulse generation from the bidirectional erbium-doped all-fiber ring laser hybridly mode-locked with a coaction of a single-walled carbon nanotube-based saturable absorber and nonlinear polarization evolution that was introduced through the insertion of the short-segment polarizing fiber. Depending on the total intracavity dispersion value, the laser emits conservative solitons, transform-limited Gaussian pulses, or highly chirped stretched pulses with almost 20 nm wide parabolic spectrum in both clockwise (CW) and counterclockwise (CCW) directions of the ring. Owing to the polarizing action in the cavity, we have demonstrated for the first time, to the best of our knowledge, an efficient tuning of soliton pulse characteristics for both CW and CCW channels via an appropriate polarization control. We believe that the bidirectional laser presented may be highly promising for gyroscopic and other dual-channel applications.

Stable similariton generation in hybrid mode-locked erbium-doped all-fiber ring laser for application in optical frequency standard

Recently similariton (or self-similar pulse) fiber lasers have attracted great attention due to their capabilities of highenergy pulse generation that could find different applications in science and industry. Moreover it is very important to reach stable pulse generation for the application as a frequency divider in optical frequency standard. Hybrid modelocking mechanism was used for obtaining stable similariton generation at 38 MHz pulse repetition frequency. It involves two types of mode-locking mechanisms in the cavity - saturation of carbon nanostructures absorber (recovery time Trt ~ 500 fs) and nonlinear polarization evolution based on the nonlinear Kerr-effect (Trt ~ 10 fs). It was shown that total intracavity dispersion should be slightly positive for generating stable similaritons with duration of less than 90 fs and spectral bandwidth of more than 50 nm at 11.2 mW output average power that could be further applied in an all-fiber MOPA setup.

Saturation parameters studies of carbon nanotube-based thin-film saturable absorbers for erbium fiber laser mode-locking

We have experimentally studied saturation behavior of Single-Walled Carbon Nanotube-based saturable absorbers at different temperatures and SWCNT concentrations in the carboxymetylcellulose polymer matrix and related it to the mode-locked erbium-doped fiber laser performance.

Sub-100 fs similariton generation in the hybrid mode-locked erbium-doped fiber ring laser

We have obtained, for the first time to the best of our knowledge, sub-100 fs similariton generation in the erbium-doped all-fiber ring laser hybrid mode-locked with Carbon:Boron Nitride Single-Walled Nanotubes in the co-action with a nonlinear polarization evolution.