Methane-based in situ temperature rise measurement in a diode-pumped rubidium laser.

We measured active zone temperature rise of an operational diode-pumped rubidium laser non-perturbatively with methane-based near-infrared tunable diode laser spectroscopy (TDLAS). For a Rb+ methane diode-pumped alkali laser (DPAL), the temperature rise was obtained. Especially, the temperature differences (∼10  K) between lasing and un-lasing cases were well identified, which demonstrated a high sensitivity of the method. To our knowledge, this is the first demonstration of extending the methane-based TDLAS method to DPAL study.