Abstract
We report here a high-power, highly efficient, wavelength-tunable nanosecond pulsed 1.7 μm fiber laser based on hydrogen-filled hollow-core photonic crystal fibers (HC-PCFs) by rotational stimulated Raman scattering. When a 9-meter-long HC-PCF filled with 30 bar hydrogen is pumped by a homemade tunable 1.5 μm pulsed fiber amplifier, the maximum average Stokes power of 3.3 W at 1705 nm is obtained with a slope efficiency of 84%, and the slope efficiency achieves the highest recorded value for 1.7 μm pulsed fiber lasers. When the pump pulse repetition frequency is 1.3 MHz with a pulse width of approximately 15 ns, the average output power is higher than 3 W over the whole wavelength tunable range from 1693 nm to 1705 nm, and the slope efficiency is higher than 80%. A steady-state theoretical model is used to achieve the maximum Stokes power in hydrogen-filled HC-PCFs, and the simulation results accord well with the experiments. This work presents a new opportunity for highly efficient tunable pulsed fiber lasers at the 1.7 μm band.
Highlights
Laser sources in the 1.7 μm band have many significant applications in material processing, mid-infrared laser generation, gas detection, medical treatment and bioimaging because there are many molecule absorption lines at this wave-band, which is located in the transparent window of living tissue [1]
We demonstrate a multi-watt, highly efficient, tunable nanosecond pulsed fiber laser source at 1.7 μm based on hollow-core photonic crystal fibers (HC-PCFs) by H2 rotational simulated Raman scattering (SRS)
It is difficult to accurately measure the second-order Raman power under our experimental condition, but it can be observed by high-sensitivity OSA and its power level can be estimated by the spectral intensity
Summary
Laser sources in the 1.7 μm band have many significant applications in material processing, mid-infrared laser generation, gas detection, medical treatment and bioimaging because there are many molecule absorption lines at this wave-band, which is located in the transparent window of living tissue [1]. Dozens of watts continuous-wave (CW) fiber lasers at 1.7 μm have been demonstrated [2,3,4], but there are few studies on high-power pulsed fiber lasers in this waveband, which have unique advantages in some applications. High-power 1.7 μm laser pulses have been proven to achieve higher resolution and larger penetration depth in multi-photon microscopy [5,6], optical coherence tomography [7], and spectroscopic photoacoustic (PA) imaging [8,9]. It is necessary to improve the power of 1.7 μm pulsed fiber lasers to meet the demands of these important applications
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
