Wavelength-tunable thulium-doped fiber laser by employing a self-made Fabry–Perot filter

Abstract

In this demonstration, we proposed a novel wavelength-tunable thulium-doped fiber laser (TDFL) with a self-made Fabry-Perot (F-P) filter. When the F-P filter was not inserted, the maximum output power of 11.1 W was achieved when the pump power was 70.2 W. The corresponding optical-to-optical conversion efficiency was 15.8% and the slope efficiency was 22.1%. When the F-P filter was inserted, the output wavelength could be tuned from 1952.9 to 1934.9 nm with the change of cavity length of F-P filter which was fixed on a piezoelectric ceramic transducer (PZT) controlled by the voltage applied to it. The full width at half maximum (FWHM) was no more than 0.19 nm. Furthermore, the wavelength fluctuations of the tunable fiber laser were kept within ±0.2 nm.

Wavelength-Flexible Thulium-Doped Fiber Laser Based on Digital Micromirror Array

“…The switching time of this type DMD used in the system is around 80 μs. The reflection loss of a DMD cover glass, as well as the self-phase modulation and nonlinear effect caused by high pump power affect the laser contour [16]. Figure 8 shows the drift of central wavelength at 1975 nm (dotted line) and the fluctuation of peak power (solid line) when the pump power is 5 W. At room temperature, the maximum power fluctuation is 0.1 dB, and the maximum wavelength drift is less than 0.05 nm within 1 h. This fluctuation is mainly caused by the fluctuation of TDFA pumping power and the doping uniformity of the gain fiber.…”

“…Thus, how to achieve high stability, narrow linewidth, and wavelength flexibility with rapid wavelength tuning or selection are the key to successful deployment for thulium-doped fibers lasers (TDFL). The current tuning devices include fiber Bragg grating (FBG) [9][10][11][12][13], F-P cavity [14][15][16], Sagnac fiber ring [17,18], Lyot filter [19][20][21], Mach-Zehnder interferometer [22][23][24], liquid crystal spatial light modulator [25], digital micromirror device (DMD) [26][27][28], and so on. Up to now, a DMD chip as a semiconductor-based addressable micromirror array has drawn considerable attention due to its flexible and fast filtering functionality in optical switching, interconnecting, and lasers.…”

“…The tuning accuracy is less than 0.1 nm. The reflection loss of a DMD cover glass, as well as the self-phase modulation and nonlinear effect caused by high pump power affect the laser contour[16].…”

Multi-wavelength-tunable thulium-doped fiber laser generation based on dual-pass Mach–Zehnder and Sagnac loop hybrid filters

“…The singlewavelength laser output tuning range was 19.4 nm, while the channel spacing for dual-wavelength laser operation was 31.6 nm [12]. Wang et al reported a TDFL employing a Fabry-Perot (F-P) filter for wavelength tuning the output, where the single-wavelength could be tuned from 1952.9 to 1934.9 nm by adjusting the F-P cavity length [13]. Zhang et al reported a six-wavelength-switchable TDFL based on a polarizationmaintaining sampled FBG, in which the wavelength fluctuation was as low as 0.71 dB [14].…”