Due to the non-linear effects in whispering gallery mode microresonators, low threshold microlaser development is possible. The lasing threshold is significantly lowered as high circulating optical intensities build up within the resonator, resulting from long photon lifetimes attributed to the ultra-high quality factor. With such characteristics in place, microresonators can operate as lasers even in complex media. We show cascaded Raman microlaser behavior in an undoped silica microsphere in air and HEPES buffer environments. The first emission peak is at around 800nm with a pump source of around 771nm. The lowest obtained threshold of the first emission line is 105μW in air and a higher threshold power of 760μW is required in buffer. Cascaded behavior of up to ten lasing peaks has been observed in air and up to two peaks were seen in buffer.

Date Published: 11 March 2013
PDF: 9 pages
Proc. SPIE 8621, Optical Components and Materials X, 86210S (11 March 2013); doi: 10.1117/12.2001926

Published in SPIE Proceedings Vol. 8621:
Optical Components and Materials X
Michel J. F. Digonnet; Shibin Jiang; J. Christopher Dries, Editor(s)