Multi-wavelength fiber lasers operated in stretched-pulse mode-locked regimes with a very compact configuration

Abstract

A novel and compact configuration for the generation of tunable multi-wavelength fiber ring lasers by exploiting the intracavity birefringence filter is demonstrated. The fiber laser is passively mode locked by using a nonlinear polarization rotation technique. A single polarization controller (PC) and a polarization-dependent isolator combined with birefringence act as a tunable comb filter and the mode locker to generate the single-wavelength ultrafast oscillation and multi-wavelength lasing by finely adjusting the PC. Multi-wavelength lasing of up to 50 lines with a wavelength spacing of 0.8 nm within a 3 dB bandwidth has been obtained. The total group velocity dispersion of the ring cavity is designed to the near-zero regime, which indicates a stretched-pulse mode-locked state.

Large dynamic range operation of ultra-higher number MWFLs affected by MZI-SI

“…Their achievement was supported by the twin-core fiber-based MZI [6]. In the latest report, Yu Huang used the NPR technique and mentioned over 75 filter lines within a 60 nm span with channel spacing of 0.8 nm [13]. From our previously reported manuscript, we successfully generated at least 22 flattened transmission filter lines through a composite ring cavity [22].…”

“…An appropriate multichannel optical filter must be incorporated into the laser cavity to achieve a multiwavelength operation. From previous reports, a lot of approaches have been proposed to realize the multiwavelength fiber lasers using different types of comb filters including the Lyot-Sagnac filter [10][11][12], nonlinear polarization rotation (NPR) [10] and fiber Bragg grating-based Fabry-Perot filter [13]. Moreover, another option for the comb filter is a Sagnac loop interferometer (SI) [14] and a Mach-Zehnder interferometer (MZI) [6,15,16].…”

Developing High-Energy Dissipative Soliton 2 μm Tm3+-Doped Fiber Lasers

“…Conventionally, generation of short pulses from fiber systems is achieved by the soliton mode-locking mechanism. Various passive mode-locking techniques can be employed, including the nonlinear polarization rotation (NPR) [9,10], the nonlinear loop mirror [11,12], and the saturable absorber method [13,14]. However, pulse energy of traditional solitons (with anomalous net cavity dispersion), which is based on the balance of dispersion and nonlinearity, is usually limited by the soliton area theorem [15,16] or the pulse peak power clamping effect [17,18] to less than 1 nJ.…”

High-energy harmonic mode-locked 2 μm dissipative soliton fiber lasers

“…Ultrafast fiber lasers in the 2 μm region have attracted a great deal of interest in recent years due to their wide range of applications in optical sensing, medical treatment, material processing, and nonlinear microscopy, etc [1][2][3][4][5]. To generate ultrafast laser pulses, various passive mode-locking techniques can be employed, including the nonlinear polarization rotation (NPR) [6,7], nonlinear loop mirror [8,9], the saturable absorber method [10,11], etc. However, conventional soliton mode-locking (with anomalous net cavity dispersion) can only produce limited pulse energy due to the pulse peak power clamping effect [12].…”