Comparison of temperature sensing of low-loss Er3+-doped silicate glass microsphere laser under different pump wavelengths

Abstract

A packaged low-loss Er3+-doped silicate glass microsphere laser is demonstrated, whose temperature sensing characteristics at different pump wavelengths are studied comparatively. An active microsphere with ultrahigh Q-factor beyond 107 is prepared by an optimized material scheme with decreased compositions and an improved arc-discharge method. The microsphere can excite lasing in 1550 nm band under both 980 and 1480 nm pumping with low threshold powers of ∼96 and ∼148 μW, respectively. Furthermore, a simple and efficient method is utilized to package the microsphere laser for enhancing the stability of laser emission. The movable device can be applied for temperature sensing with high sensitivities of 18.82 and 19.86 p.m./°C under 980 and 1480 nm pumping, respectively. And the measurable temperature range is 15 °C wider under 980 nm pumping compared with 1480 nm pumping, which is due to the higher fluorescence intensity resulting from the quicker population inversion under 980 nm pumping. The packaged microsphere device has great potential for lasing and temperature sensing applications, with the advantages of enhanced robustness and high temperature sensitivity.