Tunable single-longitudinal-mode fiber laser based on a chirped fiber Bragg grating

Research Progress of Wide Tunable Bragg Grating External Cavity Semiconductor Lasers

“…It was continuously tuned at 35 nm (1535~1570 nm) with a linewidth less than 0.04 nm. Wang et al [57] reported a tunable laser based on chirped FBG. The laser was tuned continuously for 30 nm (1535~1565 nm), with a SMSR greater than 50 dB and linewidth less than 8.5 kHz.…”

Compound Cavity Passively Q-Switched Single-Longitudinal-Mode Diode-Pumped Laser

“…From a practical standpoint, lasers which operate with a SLM must have an effective means of eliminating the spikes created by the beat frequency of adjoining longitudinal modes; this is because these spikes are the most common source of damage to laser system components [12][13][14]. A number of methods have been used to produce SLM output from solid-state lasers include twisted-mode cavities (TMC) [15], ring cavities [16], the application of etalons or gratings [17][18][19], microchip lasers [15,16], and seed injection lasers [20,21]. However, it should be noted that many of these approaches yield laser outputs with quite low SLM ratio (herein defined as the ratio of the number of single longitudinal mode pulses to the total number of pulses in a certain time).…”

“…The prior literature shows that the primary approaches to generating SLM output are based on threshold regulation and mode competition enhancement [18][19][20][21][22][23][24]. In comparison to ring cavities, it is commonly shown that standing wave cavities can generate higher energy pulses with narrower pulse width and with minor beam distortion.…”

Widely tunable sub-kHz linewidth Tm3+-doped single-frequency fiber laser

“…Up to now, tunable T-SFFLs with several different wavelength-tunability methods have been demonstrated successfully. [8][9][10][11][12] Most fiber cavity technologies can be mainly classified into two types: short linear-cavity and ring-cavity. Because of the strong limitation on cavity length, the short linear-cavity only implements a narrow wavelength tuning bandwidth (generally less than 2 nm).…”

“…Usually, the T-SFFLs contain two mainly functional portions: wavelength-tunability device and single-longitudinal-mode (SLM) lasing device. The former is the most essential element of a tunable fiber laser, such as fiber Bragg grating (FBG), 9,10) fiber Fabry-Pérot tunable filter (FFP-TF), 11,12) Lyot filter, 13,14) Sagnac loop, 15,16) and single-mode-multimode-single-mode fiber structure. 17,18) However, due to a small longitudinal mode spacing of the ring-cavity and large bandwidth of the tunable devices, other necessary optical components must be combined and employed in fiber laser for ensuring a stable SLM output.…”