1700 nm and 1800 nm band tunable thulium doped mode-locked fiber lasers

Abstract

This paper presents short wavelength operation of tunable thulium-doped mode-locked lasers with sweep ranges of 1702 to 1764 nm and 1788 to 1831 nm. This operation is realized by a combination of the partial amplified spontaneous emission suppression method, the bidirectional pumping mechanism and the nonlinear polarization rotation (NPR) technique. Lasing at emission bands lower than the 1800 nm wavelength in thulium-doped fiber lasers is achieved using mode confinement loss in a specially designed photonic crystal fiber (PCF). The enlargement of the first outer ring air holes around the core region of the PCF attenuates emissions above the cut-off wavelength and dominates the active region. This amplified spontaneous emission (ASE) suppression using our presented PCF is applied to a mode-locked laser cavity and is demonstrated to be a simple and compact solution to widely tunable all-fiber lasers.

Advanced multimodal laser imaging tool for urothelial carcinoma diagnosis (AMPLITUDE)

“…Other possible approaches to design fiber pulsed sources operating in the spectral region around 1.7 µm include Raman shifting the pulsed radiation emitted by an Er-fiber laser [17,23] and special Tm-doped active fibers in combination with optical elements suppressing amplification at 1.85 µm [24,25]. The all-fiber femtosecond Raman-based laser approach was notable for the shortest pulses (65 fs [17]) in this wavelength region so far.…”

“…Tm-doped fiber lasers operating at 1.7 µm are intrinsically more efficient than Bi-doped fiber lasers and higher level doping allows shorter cavity lengths resulting in higher pulse repetition rates [24]. Progress in the fabrication of highly effective Tm-doped fibers enabled our team in 2016 to demonstrate for the first time a widely tuneable, mode-locked fiber laser capable of producing sub-picosecond pulses between 1705 and 1805 nm [24]. This initial success was further expanded by using a specially designed photonic crystal fiber, which enabled two tuning ranges (1788-1831 nm and 1702-1764 nm) of a thulium doped mode-locked all-fiber laser [25].…”

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

“…The rapidly increasing enhancements in communication technology and the requests for wide bandwidth opts for another region of wavelength [3] which is the 2000 nm or 2 µm region [4][5] with thulium-doped fiber lasers (TDFLs) being the suitable candidate [6][7][8]. 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].…”

Thulium doped fiber based lasers and amplifiers

“…For a soliton pulse fiber laser based on Tm 3+ -doped fiber, the shortest wavelength reported so far is 1702nm [11]. For noise-like pulse TDFL, Sobon et al achieved an ultra-broadband noise-like pulse from a normal dispersion mode-locked TDFL with a 10 bandwidth of over 300nm spanning from 1830nm to 2140nm [112].…”

“…On the other hand, however, TDF based pulsed fiber lasers at wavelength below 1750 nm are only few reported. In[11], Emami reported a tunable mode-locked TDFL in the region 1702-1764 nm with pulse duration around 2.55 ps at 1730 nm.…”