Raman scattering of an ultrashort resonant probe pulse in a monatomic gas

Aleksey I. Alekseev, O. V. Zhemerdeev

Valery Alexandrovich Astapenko, N. N. Moroz

Resonant scattering of ultrashort laser pulses (ULPs) in the vicinity of spectral doublets in monatomic lithium and sodium vapors is studied theoretically. The scattering probability over the entire time of pulse action is calculated as a function of various parameters of the problem (carrier frequency and ULP duration, as well as vapor pressure and temperature). It is shown that the dependence of the total scattering probability on the pulse duration is generally nonlinear by nature.

A. I. Alekseev

Tun Wang, Susanne F. Yelin

Yujiro Eto, Hideaki Kano, Masahiro Takeoka

We theoretically investigate coherent anti-Stokes Raman scattering (CARS) driven by bright twin beams with sum-frequency generation (SFG) readout. Expressing the SFG output in terms of quantum-field correlation functions yields multiple correlation structures with distinct properties associated with different interaction pathways on the bra and ket sides. Among them, frequency correlations between the CARS probe and SFG gating fields enable the two fields to act collectively as an effective narrowband probe, avoiding probe-induced spectral convolution. When this behavior appears on either the bra or ket side, the other retains Raman relaxation information as if probed by an ultrashort pulse.

Sarah Gundry, M. Anscombe, A M Abdulla +4 more

We present a detailed experimental investigation into the off-resonant preparation of a vibrational coherence for multiorder Raman generation. In particular, the importance of the balance between the conflicting requirements for generating a strong coherence and for adiabatic evolution of the system are examined. For the parameters accessible in our experiment, we find that the strongest frequency modulation occurs under conditions for which there is some nonadiabatic behavior, and the coherence is less than the peak value obtainable. We investigate the modulation of a narrowband probe pulse, and an ultrashort probe pulse, in the coherently prepared medium, and demonstrate efficient modulation of both probe pulses resulting in the generation of $360\phantom{\rule{0.3em}{0ex}}\mathrm{THz}$ bandwidth fields. This system therefore has an application in the field of subfemtosecond pulse generation.