Noise-like rectangular pulses in a mode-locked double-clad Er:Yb laser with a record pulse energy<xref rid="cpb_29_1_014202fn1" ref-type="fn">*</xref><fn id="cpb_29_1_014202fn1"><label>*</label><p>Project supported by the National Natural Science Foundation of China (Grant Nos. 61435009, 61235008, and 61405254).</p></fn>

Noise-like rectangular pulses in a mode-locked double-clad Er:Yb laser with a record pulse energy**

Project supported by the National Natural Science Foundation of China (Grant Nos. 61435009, 61235008, and 61405254).

Wu Tianyi¹, Dou Zhiyuan¹, Zhang Bin^{1, 2, 3}, Hou Jing^{1, 2, 3, ‡}

Properties of obtained mode-locking pulses at a 1.186 MHz repetition rate in our configuration. (a) Pulse duration and peak power against the pump power. (b) Average output power and single pulse energy against the pump power. (c) Pulse shape evolution for the pump power of 0.976 W, 2.4 W, 3.82 W, 5.18 W, 6.54 W, 7.9 W, and 8.7 W. (d) Autocorrelation trace of the pulses in the scale of 50 ps. (e) Spectrum at the pump power of 8.7 W. (f) RF spectrum at the fundamental frequency with the resolution of 30 Hz. Inset: Broadband RF spectrum (100 MHz span).