No Arabic abstract
In this work, we present a high pulse energy multi-wavelength Raman laser spanning from 1.53 um up to 2.4 um by employing the cascaded rotational stimulated Raman scattering (SRS) effect in a 5-m hydrogen (H2) -filled nested anti-resonant fiber (NARF), pumped by a linearly polarized Er/Yb fiber laser with a peak power of ~13 kW and pulse duration of ~7 ns in the C-band. The developed Raman laser has distinct lines at 1683 nm, 1868 nm, 2100 nm, and 2400 nm, with pulse energies as high as 18.25 uJ, 14.4 uJ, 14.1 uJ, and 8.2 uJ, respectively. We demonstrate how the energy in the Raman lines can be controlled by tuning the H2 pressure from 1 bar to 20 bar
We report on 33 % efficient generation of the first Stokes in a high concentration GeO2 fiber Raman laser pumped by a 22 W Thulium doped fiber laser. An output power of 4.6 W at 2.105 um is demonstrated.
In this letter, we present a high pulse energy Raman laser at 1946 nm wavelength directly pumped with a 1533 nm custom-made fiber laser. The Raman laser is based on the stimulated Raman scattering (SRS) in an 8-meter carbon dioxide (CO2) filled nested anti-resonant hollow-core fiber (ARHCF). The low energy phonon emission combined with the inherent SRS process along the low-loss fiber allows the generation of high pulse energy up to 15.4 {mu}J at atmospheric CO2 pressure. The Raman laser exhibits good long-term stability and low relative intensity noise (RIN) of less than 4%. We also investigate the pressure-dependent overlap of the Raman laser line with the absorption band of CO2 at 2 {mu}m spectral range. Our results constitute a novel and promising technology towards high energy 2 {mu}m lasers.
Emission at 4.6 um was observed from an N2O filled hollow core fiber laser. 8-ns pump pulses at 1.517 um excited a vibrational overtone resulting in lasing on an R and P branch fundamental transition from the upper pump state. At optimum gas pressure of 80 Torr a photon conversion efficiency of 9% and a slope efficiency of 3% was observed from a mirrorless laser. The laser threshold occurred at an absorbed pump energy of 150 nJ in a 45-cm long fiber with 85 {mu}m core diameter. The observed dependence of the laser output on gas pressure is shown to be a result of line broadening and relaxation rates.
Mid-infrared saturable absorber mirror is successfully fabricated by transferring the mechanically exfoliated black phosphorus onto the gold-coated mirror. With the as-prepared black phosphorus saturable absorber mirror, a continuous-wave passively mode-locked Er:ZBLAN fiber laser is demonstrated at the wavelength of 2.8 um, which delivers a maximum average output power of 613 mW, a repetition rate of 24 MHz and a pulse duration of 42 ps. To the best of our knowledge, it is the first time to demonstrate black phosphorus mode-locked laser at 2.8 um wavelength. Our results demonstrate the feasibility of black phosphorus flake as a new two-dimensional material for application in mid-infrared ultrafast photonics.
We describe a tunable broadband mid-infrared laser source based on difference-frequency mixing of a 100 MHz femtosecond Yb:fiber laser oscillator and a Raman-shifted soliton generated with the same laser. The resulting light is tunable over 3.0 um to 4.4 um, with a FWHM bandwidth of 170 nm and maximum average output power up to 125 mW. The noise and coherence properties of this source are also investigated and described.