We present the first demonstration of sum frequency mixing using microlensed laser diodes. The high beam quality of these diodes allows high conversion efficiency and allows us to observe all the absorption features of the 253.7 nm mercury absorption line with a single 70 GHz scan. The UV light is generated by sum frequency mixing of two circular microlensed diode lasers, one at 662 nm (50 mW, free-running) and the other at 413 nm (13 mW, external cavity system). About 50.3 nW of UV power is produced using a β-barium-borate crystal in a single-pass configuration.
Bibliographical noteFunding Information:
We thank D.P. Rhodes for his help and T. Freegarde and D. McGloin for useful discussions. We also thank B.D. Sinclair for loan of laboratory space and F. Akerboom for construction of a low vapor pressure Hg cell. This work is supported by the UK Engineering and Physical Sciences Research Council.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry
- Electrical and Electronic Engineering