Thulium-doped fiber laser utilizing a photonic crystal fiber-based optical low-pass filter with application in 17 μm and 18 μm band

Abstract

This paper describes a low pass filter based on photonics crystal fiber (PCF) partial ASE suppression, and its application within a 1.7 µm to 1.8 µm band thulium-doped fiber amplifier (TDFA) and a thulium-doped fiber laser (TDFL). The enlargement of air holes around the doped core region of the PCF resulted in a low-pass filter device that was able to attenuate wavelengths above the conventional long cut-off wavelength. These ensuing long cut-off wavelengths were 1.85 μm and 1.75 μm, and enabled a transmission mechanism that possessed a number of desirable characteristics. The proposed optical low-pass filter was applied within a TDFA and TDFL system. Peak spectrum was observed at around 1.9 μm for conventional TDF lasers, while the proposed TDF laser with PCF setup had fiber laser peak wavelengths measured at downshifted values of 1.74 μm and 1.81 μm.

Tunable dissipative soliton Tm-doped fiber laser operating from 1700 nm to 1900 nm

“…For the short-wavelength-band (<1800 nm), despite its tremendous potential for the above-mentioned applications, comprehensive investigation was not carried out until recent years due to the significantly lower gain coefficient and, as a consequence, strong dependency on low-loss components. Initial research effort focused on the continuous-wave (CW) regime of TDFLs and Tm-doped fiber amplifiers (TDFAs), including single-frequency and wavelength-tunable operation [10][11][12][13]. In these works, to suppress high gain at longer wavelengths, different approaches have been employed, such as incorporating wavelength-selective components including fiber Bragg gratings (FBGs), tunable filters, and photonic crystal fibers (PCFs), and deploying absorption characteristics of Tb 3+ and Ho 3+ ions.…”

Highly Efficient Multiple Watt Gain-Switched 1.7 μm All-Fiber Laser Pumped by 1.6 μm Harmonic Dissipative Soliton Resonance Pulses

“…Noronen et al and Chen et al have reported picosecond 1.7 μm lasers based on the carbon nanotube (CNT) [20] and the semiconductor saturable absorption mirror (SESAM) [21] respectively. Apart from using various mode-locker, nonlinear polarization rotation (NPR) [22][23][24][25][26], NALM [27] technique [28] have been also demonstrated to achieve 1.7 μm pulsed laser. However, the 1.7 μm pulsed lasers obtained in these previous reports had a poor efficiency, the pulse energy and the average power were limited to nJ-level and milliwattslevel.…”

“…In this paper, we firstly used a 1.6 μm harmonic dissipative soliton resonance (DSR) fiber laser as the pump. In comparison with the typical in-band pumping scheme of using 1.5 μm laser to generate 1.7 μm laser [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28], 1.6 μm pump can be absorbed more effectively by thulium-doped fiber [39] and leads to a lower quantum defect. More importantly, 1.6 μm pump can compensate the low pump absorption of the short-gain fiber.…”

Simulation of dual stage thulium-doped fiber amplifier using pump power distribution technique

“…Researches are motivated to focus on thulium-doped fibers (TDFs) as numerous applications are done at the 1700-2100 nm region [6,[9][10]. Thulium-doped fiber amplifiers (TDFAs) are being introduced recently due to the limitation capacity [11][12][13][14] to operate in a wider waveband as compared to EDFAs, thus garnering a broader gain spectrum [15] and possibly going beyond the conventional 1550 nm region [16][17]. This larger waveband requires higher gain and lower noise figure.…”