Diode-pumped 45 fs Yb:CALGO laser oscillator with 17  MW of peak power

Abstract

A high-power sub-50 fs diode-pumped Yb:CALGO laser oscillator is demonstrated. The peak power achieved for 45 fs pulses directly from the oscillator was 1.7 MW. To the best of our knowledge, this is the highest peak power in the sub-50 fs pulse regime that has ever been produced directly from any diode-pumped Yb-ion-doped laser oscillator to date. The shortest generated pulses were 38 fs long with 187 kW of peak power.

Diode-pumped Yb:CALGO laser with conical refraction output

“…Considering these important characteristics, Yb-ion lasers are becoming reliable in applications such as micromachining [32], optical communication [33], multiphoton microscopy [34][35][36][37][38][39] and nonlinear optics [40][41][42][43]. There are different types of Yb laser crystals available but Yb:CALGO is the most popular one because of its high thermal conductivity (6.5 W/m/K) with a 50 nm broad emission spectrum which makes it suitable for high power laser operation [44][45][46][47][48][49][50][51][52][53][54][55].…”

Sub-40-fs high-power Yb:CALYO laser pumped by single-mode fiber laser

“…In particular, ytterbium-based solid-state lasers have attracted increasing attention because of their excellent optical and thermal properties. Recently, a great number of Yb-doped materials including Yb:CaF 2 [1, 2] , Yb:CALGO [3–5] , Yb:CALYO [6] , Yb:KYW [7] , Yb:KGW [8–10] and Yb:Lu 2 O 3 [11] crystals as well as Yb:LuAG ceramic [12] have shown their capacity in generating sub-100-fs pulses with watt level average power via either pure Kerr-lens mode-locking (KLM) or combination of KLM and saturable absorber-based passive mode-locking. Among them, Yb-doped calcium aluminate crystals including Yb:CALGO and Yb:CALYO are the most attractive candidates for high-power sub-50-fs pulses generation, due to their flat emission spectra with more than 70 nm bandwidths as well as high thermal conductivity.…”

“…Up to more than 3 W average power with 45-fs pulses was obtained by Manjooran et al. [5] . Still, most of the obtained average powers from above literatures were only on the order of several tens of milli-watt, due to either the small pump power of the single-mode fiber coupled laser diodes (LDs) or the critical cavity setup restrained by the low-brightness multi-mode LDs.…”

Observation of spectral modulation coupled with broadband transverse-mode-locking in an Yb:CALGO frequency-degenerate cavity

“…In comparison, our work here demonstrates that the transverse mode can also modulate the spectrum in the broadband TML process. We note that this is understandable because the nonlinear coefficient of Yb:CALGO (n 2 ¼ 9 × 10 −20 m 2 ∕W) [18] is much less than that of the commonly used Nd:YVO 4 crystal (n 2 ¼ 4.7 × 10 −18 m 2 ∕W) [19] . Therefore, the spectral modulation effect can be confirmed to be coupled with the spatial TML effect rather than the temporal LML effect.…”