Yu. T. Mazurenko

Ultrafast time-to-space conversion of phase by the method of spectral nonlinear optics.

We propose a method for direct conversion of an ultrashort pulse into a monochromatic beam whose wave front either repeats or is related to the phase structure of the pulse or its spectrum. This can be done by sum-frequency generation of the spectrally resolved pulses. Experimentally, we projected two spectra of the same chirped pulse onto the nonlinear crystal so that the dispersions were opposite. After sum-frequency generation, a converging or diverging monochromatic beam was formed that was the analog of the pulse spectrum. We could determine the chirp value by the measurement of the wave-front radius.

Time-to-space conversion of fast signals by the method of spectral nonlinear optics

We demonstrate time-to-space conversion of fast optical signals when using sum-frequency generation of spectral decomposition waves. Spatially decomposed optical spectra of ultrashort signal and reference pulses, having opposite directions of dispersion, are projected onto the nonlinear crystal. After sum-frequency generation and optical Fourier transform the image is formed that is the spatial analog of the signal pulse.

Anti-stokes excitation of luminescence of dyes by high-power radiation

Abstract The luminescence of several dyes under laser excitation near the maximum of their emission spectra is studied. The processes of quenching and depolarization of luminescence by light and of two-photon absorption are observed.

Spectral heterodyne tomography

A novel method of optical coherent tomography—spectral heterodyne tomography—is proposed. Spectral heterodyne tomography is based on parallel heterodyne detection of a multitude of frequencies of the light backscattered by an object under study. The result of this detection is a spectral distribution of the amplitude and phase of the scattered radiation. Subsequent numerical processing allows one to find the distribution of scattering centers over the depth corresponding to the point of entrance of the incident light. The proposed method is potentially characterized by a higher efficiency as compared with the most successful approach to optical coherence tomography, based on heterodyne scanning interferometry.

Analysis of the form of ultrashort pulses by spectral nonlinear interferometry

A new method for recording the phase structure of ultrashort optical pulses is proposed that makes no use of a reference pulse. Using three-wave interactions in a nonlinear optical medium, a wave of spectral decomposition of an ultrashort pulse is transformed into a monochromatic wave. The spatial phase structure of this wave contains information on the phase structure of the pulse spectrum and on the pulse form. This structure is analyzed by shearing interferometry.