10 watt-level tunable narrow linewidth all-fiber amplifier

We report here a high-power, wavelength tunable and narrow linewidth $1.5~\unicode[STIX]{x03BC}\text{m}$ all-fiber laser amplifier based on a tunable diode laser and Er-Yb co-doped fibers. The laser wavelength can be precisely tuned from 1535 nm to 1580 nm, which covers many absorption lines of mid-infrared laser gases, such as $\text{C}_{2}\text{H}_{2}$, HCN, CO, and HI. The maximum laser power is ${>}$11 W, and the linewidth is about 200–300 MHz, which is close to the absorption linewidth of the above-mentioned gases. This work provides a suitable pump source for high-power wavelength tunable mid-infrared fiber gas lasers based on low-loss hollow-core fibers.

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Narrow-Linewidth 2 μm All-Fiber Laser Amplifier with a Highly Stable and Precisely Tunable Wavelength for Gas Molecule Absorption in Photonic Crystal Hollow-Core Fibers

Molecules ◽

10.3390/molecules26175323 ◽

2021 ◽

Vol 26 (17) ◽

pp. 5323

Author(s):

Wenxi Pei ◽

Hao Li ◽

Yulong Cui ◽

Zhiyue Zhou ◽

Meng Wang ◽

...

Keyword(s):

Photonic Crystal ◽

Fiber Laser ◽

High Power ◽

Gas Absorption ◽

Laser Linewidth ◽

Narrow Linewidth ◽

Hollow Core ◽

Mid Infrared ◽

Gas Lasers ◽

Tunable Wavelength

In recent years, mid-infrared fiber lasers based on gas-filled photonic crystal hollow-core fibers (HCFs) have attracted enormous attention. They provide a potential method for the generation of high-power mid-infrared emissions, particularly beyond 4 μm. However, there are high requirements of the pump for wavelength stability, tunability, laser linewidth, etc., due to the narrow absorption linewidth of gases. Here, we present the use of a narrow-linewidth, high-power fiber laser with a highly stable and precisely tunable wavelength at 2 μm for gas absorption. It was a master oscillator power-amplifier (MOPA) structure, consisting of a narrow-linewidth fiber seed and two stages of Thulium-doped fiber amplifiers (TDFAs). The seed wavelength was very stable and was precisely tuned from 1971.4 to 1971.8 nm by temperature. Both stages of the amplifiers were forward-pumping, and a maximum output power of 24.8 W was obtained, with a slope efficiency of about 50.5%. The measured laser linewidth was much narrower than the gas absorption linewidth and the wavelength stability was validated by HBr gas absorption in HCFs. If the seed is replaced, this MOPA laser can provide a versatile pump source for mid-infrared fiber gas lasers.

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Widely Wavelength-Tunable High Power Single-Longitudinal-Mode Fiber Laser in Mid-Infrared Waveband

Applied Sciences ◽

10.3390/app11052073 ◽

2021 ◽

Vol 11 (5) ◽

pp. 2073

Author(s):

Yi Lu ◽

Xiaogang Jiang ◽

Feihong Chen ◽

Chenlong Lu ◽

Sailing He

Keyword(s):

Fiber Laser ◽

High Power ◽

External Cavity ◽

Longitudinal Mode ◽

Laser Wavelength ◽

Single Longitudinal Mode ◽

Mid Infrared ◽

Wavelength Tunable ◽

Narrow Bandwidth ◽

Cavity Structure

We demonstrate a mid-infrared (MIR) wavelength-tunable high-power single-longitudinal-mode (SLM) fiber laser using a compound cavity structure. The compound cavity consists of an Er-doped ZBLAN fiber perpendicularly cleaved at two-ends and an external cavity formed by a fiber end-face and a narrow bandwidth ruled reflective diffraction grating. SLM operation is achieved through the combined effects of the narrow bandwidth grating and the compound cavity. By rotating the grating, the laser wavelength can be continuously tuned over 100 nm from 2705 nm to 2806 nm with the SLM operation maintained. High output power up to 450 mW is achieved under the SLM regime.

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