Femtosecond Yb-doped tapered fiber pulse amplifiers with peak power of over hundred megawatts

Abstract

Ultrafast fiber lasers combining high peak power and excellent beam quality in the 1-µm wavelength range have been explored to applications in industry, medicine and fundamental science. Here, we report generation of a high-energy sub 300 fs polarization maintaining fiber chirped pulse amplification (CPA) system by using a Yb-doped large mode area tapered polarization maintaining (PM) optical fiber with the core/cladding diameters of 35/250 µm at the thin end and 56/400 µm at the thick end. The taper fiber design features a confined core for selective gain amplification and multi-layer cladding for enhanced suppression of higher order modes. In this regime, we have demonstrated 266 fs pulse amplification with peak power of up to 132 MW at a repetition rate of 2 MHz and high beam quality with measured M2 value of 1.1∼1.3. To the best of our knowledge, it is the highest peak power reported in such tapered Yb-doped fiber (T-YDF) amplifier in the femtosecond regime. This work indicates the great potential of the T-YDF to realize further power scaling, high laser efficiency, and excellent beam quality in high-power femtosecond fiber lasers.

Femtosecond Laser Direct Writing of Flexible Electronic Devices: A Mini Review

“…Typical commercial Ti: sapphire laser systems can produce pulses with tens of fs duration at about 800 nm wavelength and up to 250 kHz repetition rate [30]. The ytterbium fiber, on the other hand, can deliver power in the range of a few watts to a hundred watts with pulse widths of 0.2 to 10 ps and up to 100 MHz repetition rate [31,32]. These pulses are then amplified to microjoule and millijoule levels for machining applications using a technique known as chirped pulse amplification [33].…”

Picosecond Pulse Tapered Fiber Amplifier Operated near 1030 nm with Peak Power up to 1 MW

“…As a consequence, in the thick part, it is quite difficult to obtain a core diameter significantly larger than 40-50 µm. In this case, it is worth mentioning an alternative approach [30], where tapered fibers are realized with an initially non-single-mode core at the thin end. Acceptable beam quality in this case is achieved by winding a thin part of the tapered fiber on a coil of small diameter, which allows removal of a significant part of the higher modes from the core.…”

Indium antimonide-based saturable absorber to demonstrate passively Q-switched and mode-locked operation

“…In recent decades, ultra-fast fiber lasers have caught much notice because of their outstanding peak power, short pulse width, compactness, and high environmental stability [1][2][3][4][5]. Nowadays, pulsed lasers have been found in lots of applications such as sensing, medicine, industrial manufacturing, microscopic imaging and optical communication, etc [6][7][8][9][10][11][12].…”