Compact Tm-doped fibre laser pumped by a 1600nm Er-doped fibre laser designed for environmental gas sensing

Abstract

In this work, the compact all-fibre linear Erbium (Er)-doped fibre lasers, operating at wavelengths of 1584 nm and 1600 nm have been described and optimized, with an aim to achieve better pumping conditions for a Thulium (Tm)-doped fibre laser. Optimization of the system has been carried out involving the studies on the different lengths of the Er-doped fibre and the different grating pairs used to achieve 173.5 mW of laser power at 1600 nm under bidirectional pumping at 980 nm. The designed Er-doped fibre laser at 1600 nm has been utilized successfully to pump longer wavelength Tm-doped fibre laser. The obtained laser power (output of Tm-doped fibre laser) of 35.5 mW at 1874 nm and 10.6 mW at 1995 nm is effective for environmental gas sensing, as these wavelengths align well with the absorption spectra of greenhouse gases such as CO 2. The laser offers high power (tens of milliWatts), good directionality and a compact overall packaging with the diode pumping, making them ideally suited to 'in-the-field' use. .

Generation of bright‐dark Q‐switched pulse pair in thulium‐doped fiber laser cavity with titanium aluminum carbide absorber

“…Q-switched fiber lasers operating in the mid-infrared region near 2 μm have received tremendous research attention in recent years, owing to their wide area of applications including optical communication, materials processing, spectroscopy, and light detection and ranging. [1][2][3][4][5] These lasers can be constructed using thuliumdoped fiber (TDF) or thulium-holmium codoped fiber (THDF) as an active medium. Q-switched pulses in the 2μm region can be passively produced by inserting a saturable absorber (SA) device into the TDF laser (TDFL) or THDF laser cavity to modulate the loss or Q-factor.…”

“…Q‐switched fiber lasers operating in the mid‐infrared region near 2 μm have received tremendous research attention in recent years, owing to their wide area of applications including optical communication, materials processing, spectroscopy, and light detection and ranging 1–5 . These lasers can be constructed using thulium‐doped fiber (TDF) or thulium–holmium codoped fiber (THDF) as an active medium.…”

Femtosecond Laser Plane-by-Plane Inscribed Cavity Mirrors for Monolithic Fiber Lasers in Thulium-Doped Fiber

“…Thulium fiber lasers (Tm-FL) operating with laser wavelengths between 1.6 to 2.1 μm [ 4 , 21 , 22 , 23 ] were proposed for various applications, including as a biomedical tool for tissue soldering [ 24 ] and lithotripsy [ 25 ], while they are considered as highly efficient lasers for material processing applications, especially for polymer processing [ 26 , 27 ] since the emission bands of Tm-lasers coincide with the absorption bands of the polymers [ 28 ]. In addition, their applications are extended to greenhouse atmospheric gas sensing [ 29 , 30 ], such as the measurement of CO 2 concentration. It is well known that CO 2 has a strong fingerprint between 1.8 μm and ~2 μm [ 31 ], which coincides with the emission band of Tm-lasers.…”

Switchable single- and dual-wavelength thulium/holmium co-doped fiber laser with single-longitudinal mode output

“…Due to the wide applications in environmental gas sensing [1], free-space data transmission [2], dual-comb spectroscopy [3], material processing [4] and surgery [5], optical fiber lasers operating at 2 µm band have gained increasing research interest in fields of scientific research and industry with the * Authors to whom any correspondence should be addressed. gain medium of thulium-doped, holmium-doped or thulium/holmium co-doped fiber (THDF).…”