Compact 80 W, 1 MHz Femtosecond Chirped Pulse Amplification Laser System Based on a Yb-Doped Fiber and a Yb:YAG Thin Rod

Abstract

We present a hybrid chirped pulse amplification (CPA) laser system based on Yb-doped fiber and Yb:YAG thin rod. The laser system demonstrates a novel approach to generate high average power up to the 100-W level by using a Yb:YAG thin rod without pump guiding at room temperature. A Yb-doped allfiber laser with an output power of 7 W and a repetition rate of 1 MHz is amplified to an output power of 126.2 W in simple and compact two-stage amplifiers consisting of a single fiber crystal (SCF) and a Yb:YAG thin rod. To the best of our knowledge, this is the highest output power of Yb:YAG thin-rod amplifier with good beam quality obtained without pump guiding at room temperature. After using a thin-film polarizer (TFP) to remove the thermal depolarization, a linearly polarized ultrashort pulse laser with an average power of 115.2 W is obtained. An output power of 80.6 W with a pulse width of 580 fs is achieved after pulse compression. The central pulse contains 84.1% of the total pulse energy, corresponding to a pulse peak power of 116.9 MW.

A compact femtosecond laser system based on homemade Yb:YAG single crystal fiber gain module with high pulse energy and good beam quality

“…In 2022, Xu et al obtained linear polarized laser power of 115.2 W at 1 MHz based on the Taranis module and Yb:YAG thin-rod amplifier before pulse compression. The measured beam quality was 𝑀 𝑥,𝑦 2 = 1.83 x 1.61 [12]. In 2023, Li et al achieved laser power of 138.6 W at 1MHz by using single-stage SCF amplifier.…”

396-MHz 1030-nm hybrid CPA amplifier based on fiber-Yb:YAG crystal thin rod

“…While there have been numerous studies on the fiber-rod crystal Yb:YAG hybrid amplification system, most of these systems are configured with high cost, limiting their wide application in middle and low-end industrial processing [13][14][15][16][17] . On the other hand, domestic research in this area started relatively late and is mainly confined to experimental research [18][19][20] . Therefore, it is crucial to explore a low-cost, stable, and reliable ultrashort pulse amplifier that can be widely utilized in industrial processing.…”

Hundred watt level and high energy compact hybrid fiber femtosecond laser with good beam quality

“…Amplifiers with a fiber solid-state hybrid structure can overcome the limitations of the nonlinear effect to some extent while maintaining most of the advantages of fiber lasers [7][8][9]. However, there are some difficulties with this kind of laser structure.…”