Improved high-field laser characteristics of a diode-pumped Yb:LiYF4 crystal at low temperature

We have demonstrated a diode-pumped Yb:LiYF4 laser oscillator at liquid nitrogen temperature in free-running mode. The obtained laser gain was 21 cm-1, which was 15 times as high as that at room temperature. The effective tuning range was broadened to 35 nm due to absorption spectral narrowing.