2-$\mu\hbox{m}$ Tm-Doped All-Fiber Pulse Laser With Active Mode-Locking and Relaxation Oscillation Modulating

Abstract

We report on the actively mode-locked and relaxation-oscillation-modulated 2-m all-fiber laser, using an electronic optical phase modulator with fiber pigtail. Linear-cavity and ring-cavity fiber lasers with Tm-doped fiber were set up with a center wavelength around 1.95 m. Actively mode-locked stable pulse train was generated with a repetition rate of 11.884 MHz (linear cavity) and 12.099 MHz (ring cavity), and the duration of the pulse was 816 ps and 446 ps, respectively. The stable pulse train with a duration of 5.885 s and a repetition rate of 4-18 kHz was generated by actively modulating the relaxation oscillation of the linear-cavity fiber laser. Similar results for the ring-cavity fiber laser were 1.554 s and 6-26 kHz, respectively. All the stable pulse trains' energy fluctuations were less than 7%.

Pulsed Yb3+-doped fiber laser operating at 1011 nm by intra-cavity phase modulation

“…When the function generator works around the relaxation oscillation of the fiber laser, this fiber laser can also generate stable pulse train [14][15][16]. For example, by turning the frequency of the FG to 27.778 kHz, the pulse train shown in Fig.…”

“…In this experiment, the difference from the mode-locking regime mentioned above is that the pump power would definitively affect the shape of the pulse train. This is because of the connection between the pulse train and the relaxation oscillation phase of the fiber laser [16].…”

Two kinds of novel tunable Thulium-doped fiber laser

“…Because the water vapor and some important greenhouse gas molecules in the atmosphere exhibit characteristic absorption lines around 2 μm wavelength region [1][2], TDFLs can be used in a wide range of applications, such as noninvasive surgery, remote sensing, laser radar, free-space telecommunications [3][4][5][6], etc. Many theoretical and experimental studies on TDFLs have been reported [7][8][9][10][11][12][13][14][15][16][17][18]. However, most of previously reported research mainly concentrated in high power [7][8][9][10][11] or pulse lasing [13][14][15][16][17][18].…”

2 μm high repetition frequency active mode-locked pulsed fiber laser and digital modulation

“…In 2013, Wang Xiong et al published an active mode-locked thulium-doped fiber laser with an all-fiber structure, whose repetition frequency mode-locked pulse laser can reach 11.884 MHz and 12.099 MHz. [15] Kneis et al reported an active mode-locked thulium-doped fiber laser with high average power and tunable wavelength in 2015. [16] In 2016, Wang et al reported an active mode-locked thulium-doped fiber laser using pump modulation.…”