Abstract
Since the inception of the second-order nonlinear frequency conversion in 1961, enhancing the inherent low conversion efficiency has been a primary objective. This goal has been successfully accomplished through the utilization of cm-long nonlinear crystals characterized by high quality and nonlinearity, coupled with versatile phase-matching strategies and high-power mixing lasers. However, the reliance on lengthy nonlinear crystals and the necessity for precise phase-matching introduce stringent tolerances on acceptance angles and spectral bandwidths for the interacting fields, thereby constraining its widespread applicability in scientific and industrial domains. This challenge is addressed by combining a broadly tunable ∼5 mW quantum cascade laser operating in the 9.5–12.5 µm range with upconversion detection in ∼100 µm long AGS crystals. Using a tightly focused continuous wave Nd:YVO4 laser with 20 mW output power and spatial filtering of the upconverted beam lead to a SNR of 55 for 50 µs averaging time sufficient for many applications.
© 2024 Optica Publishing Group
Full Article | PDF ArticleMore Like This
Ajanta Barh, Christian Pedersen, and Peter Tidemand-Lichtenberg
Opt. Lett. 42(8) 1504-1507 (2017)
Rasmus L. Pedersen, Peter Tidemand-Lichtenberg, and Christian Pedersen
Opt. Lett. 47(21) 5622-5625 (2022)
Défi Junior Jubgang Fandio, Aswin Vishnuradhan, Eeswar Kumar Yalavarthi, Wei Cui, Nicolas Couture, Angela Gamouras, and Jean-Michel Ménard
Opt. Lett. 49(6) 1556-1559 (2024)