Application of new nonlinear-optical crystals for development of novel methods for nonlinear-optical conversion of solid-state laser radiation into mid-infrared range presents an important task of modern infrared photonics. Significance of this challenge is caused not only by limited choice of solid-state sources of coherent radiation in mid-infrared range, but also by potential applications of such sources in science, technology, medicine, and biology. Efficient method of optical frequency down-conversion is the difference-frequency generation (DFG) allowing the single-pass conversion of the pump and signal optical frequencies lying in the near-IR range into the mid-IR idler wave. The narrowband, frequency stable signal wave for the DFG is generated in our setup by the stimulated Raman scattering (SRS) in a cubically nonlinear crystal (CaCO3, BaWO4, or diamond). In order to present a comparative study, the LiGaSe2 and LiGaS2 crystals with the equal length of 8 mm were used. Narrowband idler waves at the discrete wavelengths of 4.6 / 5.4 / 7.5 / 9.2 μm and high pulse energies in the range 10 - 50 μJ were generated. The measured linewidths were close to the monochromator resolution limit of < 2 cm-1 (~10 nm @ 7.5 μm) and they can be even narrower. It can be supposed that the idler wave linewidth should be comparable with the Raman mode linewidth (ΔνR = 1.2 2.7 cm-1). Generation at 10.8 μJ was achieved in LiGaSe2 only and the output energy was at in the order of ~100 μJ (close to the measuring probe resolution limit).
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.