Twelve-Wavelength-Switchable Thulium-Doped Fiber Laser With a Multimode Fiber Bragg Grating

Abstract

In this article, a precisely controlled, switchable thulium-doped fiber laser (TDFL) with high optical signal-to-noise ratio (OSNR) is proposed and demonstrated. A home-made multimode fiber Bragg grating (MMFBG) with multireflection peaks was used as an optical filter to select the desired lasing channel. Using a manually controlled fusion splicer, the axial misalignment was applied between the single mode fiber and the MMFBG to switch the output wavelength. In the experiment, the number of switchable lasing lines was up to 12, and the fluctuation of the center wavelength and output power was less than 0.03 nm and 0.67 dB, respectively. A maximum slope efficiency of 1.3% was obtained when the axial misalignment was 0 μm, and the OSNR was higher than 65 dB. In addition, the proposed fiber laser was used as an optical fiber laser sensor to quantify the strain applied on the MMFBG, and a sensitivity of 1.16 pm/με was obtained.

Pumping scheme for Holmium‐doped fiber amplifiers using traditional 1480 nm pumps exploiting cascaded lasers implemented using fiber Bragg gratings

“…Various essential parameters of EDF, TDF, and HDF such as core radius, doping radius, numerical aperture, and so forth, are taken in line with the specs of commercial components or experimental records as mentioned in Mirza and colleagues. 4,22,[25][26][27][28][29] The slope efficiency (SE) is defined as the efficiency by which the pump power is converted into the lasing signal power. It is calculated from the slope of the curve obtained from plotting the lasing output power versus the pump power.…”

“…In this work, the EDF length and doping concentration of $${\text{Er}}^{3+}$$ are optimized in the first laser after which we optimize the second laser by optimizing the length of TDF and doping concentration of $${\text{Tm}}^{3+}$$ such that each laser is attached with each other. Various essential parameters of EDF, TDF, and HDF such as core radius, doping radius, numerical aperture, and so forth, are taken in line with the specs of commercial components or experimental records as mentioned in Mirza and colleagues 4,22,25–29 . The slope efficiency (SE) is defined as the efficiency by which the pump power is converted into the lasing signal power.…”

Thulium-doped fiber laser with switchable single-wavelength output using polarization-dependent loss

“…To realize switchable output in TDFLs, different wavelength switchable mechanisms have been proposed-for example, an inline acousto-optic tunable bandpass filter [26], a digital micromirror array [27], a diffraction grating [28], polarization-dependent loss (PDL) [29], changing the temperature [30], applying strain [31], and enforcing axial misalignment [32]. It should be noted that digital micromirror arrays and diffraction gratings are expensive, making such TDFLs costly.…”