Vibrational and Rotational Raman Stokes Generation in a High Finesse Cavity

Carlos Russo, H. G. Barros, Andreas Stute +9 more

V. N. Lugovoǐ

Geon Joon Lee, Kento Hara, M. Katsuragawa +1 more

The solid para-hydrogen film was prepared by depositing the para-hydrogen vapor onto a sapphire substrate. From the stimulated Raman scattering experiment using two ns-lasers whose laser-frequency difference is equal to the fundamental vibrational transition of the solid para-hydrogen, we observed the collinear generation of Raman sidebands. The high-order Raman sidebands were obtained under the strong pumping intensity (≥230 MW/cm 2 ). The generated five anti-Stokes(AS)-Raman sidebands extend from ultraviolet (292 nm for AS 5 band) to visible (565 nm for AS 1 band) region. Also, we found that the first AS-Raman signal shows weak rotational components as well as a strong vibrational line. From the experiment that makes the multimode probe beam beat with the prepared Raman coherence, we found that the prepared Raman coherence replicates the probe beam to its Raman sidebands. The frequency conversion efficiency from the probe beam to the first AS-Raman sideband rises to the maximum (4.7%) at 284 MW/cm 2 , and then falls with the increase of the pumping intensity. This is thought to be due to the fact that some molecules in the first vibrational level incline to go to the higher vibrational level under the higher pumping intensity. For the strong pumping intensity (290 MW/cm 2 ), four anti-Stokes and one Stokes Raman sidebands of the probe beam were generated.

David C. Gold, Joshua J. Weber, Deniz D. Yavuz

We demonstrate an optical modulator at a frequency of 90 THz that has the capability to modulate any laser beam in the optical region of the spectrum. The modulator is constructed by placing deuterium molecules inside a high-finesse cavity and driving a vibrational transition with two continuous-wave laser beams. The two beams, the pump and the Stokes, are resonant with the cavity. The high intra-cavity intensities that build up drive the molecules to a coherent state. This molecular coherence can then be used to modulate an independent laser beam, to produce frequency up-shifted and down-shifted sidebands. The beam to be modulated is not resonant with the cavity and thus the sidebands are produced in a single pass.

Franck Billard, David Gachet, Hervé Rigneault

Shin-ichi Zaitsu, Kohei Uemoto, Noritada Kaji

We demonstrate phase-matched cavity-enhanced coherent Stokes Raman scattering in hydrogen gas using a high-finesse dispersion-compensated cavity, achieving over 10 9 enhancement compared with spontaneous Raman scattering.