The Use of Ultrashort Picosecond Laser Pulses to Generate Quantum Optical Properties of Single Molecules in Biophysics

S. Kahra, Günther Leschhorn, Markus Kowalewski +8 more

Tatsuo Yajima, Yoichi Taira

The dynamical properties of a third-order nonlinear optical process, in which two incident light pulses with wave vectors k 1 and k 2 generate a light wave with 2 k 2 - k 1 in resonant media, are discussed with particular attention to the effect of transverse relaxation time T 2 . It is shown that the correlation trace (output light energy vs incident pulse separation) for this process provides a general means of obtaining information on ultrashort T 2 for both the homogeneously and inhomogeneously broadened transitions, and for both t p (pulse width)< T 2 and t p > T 2 . An experimental demonstration for t p > T 2 is given by using a dye molecule and a picosecond light source.

罗嗣佐 Luo Sizuo, 陈洲 Chen Zhou, 李孝开 Li Xiaokai +2 more

Adi Natan, Yaron R. Silberberg

David G. Sarkisyan, A. A. Badalian, S O Sapondzhyan +1 more

Electron stimulated Raman scattering in atomic cesium vapor was used in efficient conversion of the freqeuncy of the second harmonic to the infrared range in the case of picosecond YAG and neodymium phosphate glass lasers. The tuning range of ultrashort pulses was 2.21-2.55μ, the spectral width of the output pulses did not exceed 2 cm−1, and the quantum efficiency of the conversion process was 10%. In addition to tunable ultrashort pulses, picosecond pulses at fixed wavelengths of 3.1 and 0.88μ were generated.

Alexander Gabriel Löhr, Misha Ivanov, Margarita Khokhlova

Control over the time dependence of the refractive index of a material allows one to modify and manipulate the properties of light propagating through it. While metamaterials provide a promising avenue in this context, another route has been extensively explored by the ultrafast community - the so-called molecular modulators. Indeed, impulsively-aligned diatomic molecules provide a unique medium, where periodic rotational revivals induced by a pump pulse persist for tens of picoseconds, offering an excellent opportunity for the controlled modification of the refractive index and, therefore, of femtosecond laser pulses propagating through these media. Here we present an analytical theory which describes this process and stumble across a novel mechanism revealing exponential transformations of the probe pulse - its compression, amplification and frequency up-conversion. In particular, our analytical results predict the generation of amplified ultrashort (about 20 fs) ultraviolet pulses centered around 550 nm, starting with near infrared input pulses centered on 1 μm of about 30 fs duration, under very realistic experimental conditions.