High-power tunable mid-infrared fiber gas laser source by acetylene-filled hollow-core fibers

Abstract

High-power tunable pulsed and CW mid-infrared fiber gas laser sources in acetylene-filled hollow-core fibers, to the best of our knowledge, are demonstrated for the first time. By precisely tuning the wavelength of the pump source, an amplified tunable 1.5 μm diode laser, to match different absorption lines of acetylene, the laser output is step-tunable in the range of 3.09~3.21 μm with a maximum pulse average power of ~0.3 W (~0.6 μJ pulse energy) and a maximum CW power of ~0.77 W, making this system the first watt-level tunable fiber gas laser operating at mid-infrared range. The output spectral and power characteristics are systemically studied, and the explanations about the change of the ratio of the P over R branch emission lines with the pump power and the gas pressure are given, which is useful for the investigations of mid-infrared fiber gas lasers.

Highly efficient and stable coupling of kilowatt-level continuous wave laser into hollow-core fibers

“…Different from the solid-state fiber using total reflection, the hollow-core fiber (HCF) can confine light into the hollow core with 10 to 100 μm diameters due to its special cladding structure, and it can also be filled with various kinds of gases, which provides an ideal environment for the interaction between the laser and gases due to its hollow-core structure [1] . Thus, a novel kind of laser named a fiber gas laser (FGL) was developed [2] , and great progresses have been made in this kind of laser source [3][4][5][6][7][8][9][10][11][12][13][14] . However, the power level can hardly breach 10 W; one main cause is the lack of stable and high-efficiency coupling methods of high-power lasers into HCFs.…”

Stable and Efficient Coupling of High-Power Continuous-Wave Laser With Uncooled Anti-Resonant Hollow-Core Fibers With End Caps

“…FGLs combine the advantages of traditional gas lasers and fiber lasers, which have the potential to emit higher power and longer wavelengths than fiber lasers. In the past decade, significant progress has been made in FGLs [2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Thus far, although various laser wavelengths from the visible to the mid-infrared have been demonstrated, the output laser power is only at the watt level.…”

All-Fiber Gas Cavity Based on Anti-Resonant Hollow-Core Fibers Fabricated by Splicing with End Caps

“…AR-HCFs provide an ideal environment for the interaction of laser beams and gases, making a novel kind of laser source, namely fiber gas lasers (FGLs) [5,6]. In the past few years, FGLs have obtained enormous attention because they have been demonstrated to be an effective new method for generating mid-infrared laser emission [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] in addition to traditional ways, such as solid-state lasers [20], gas lasers [21], quantum-cascade lasers [22] and rare-earth-doped fiber lasers [23][24][25]. Due to the perfect combination of the advantages of both gas lasers and fiber lasers, FGLs have the potential to achieve high-power mid-infrared lasers with abundant wavelengths and portable structures [6].…”