Superluminescence and Generation of Stimulated Radiation Under Internal-reflection Conditions

А.В. Андреев, Oleg Tikhomirov, Mikhail V. Fedotov

A. M. Bonch-Bruevich, Калитеевская Елена Николаевна, T. K. Razumova

The criteria governing the superluminescence and stimulated emission from unstable photoisomers of polymethine dyes are studied for the first ime. It is shown that this is an important factor in stimulated emission from polymethines under conditions of anti-Stokes pumping of initial stable molecule solutions. Numerical calculations are made of the gain spectra of polymethine solutions containing photoisomers pumped by radiation of varying spectral composition. Conclusions are drawn on the influence of photoisomerization on the stimulated emission characteristics of these media under different pumping conditions.

А. В. Андреев, O. Iu. Tikhomirov, Mikhail V. Fedotov

Vyacheslav F. Lebedev, E. A. Vasiliev, Ya. A. Ryvkina +4 more

Abstract— A comparative analysis has been made of the superluminescence spectra of two HPHT diamond samples with NV¯-centers with the concentration in the growth sectors {111} of NV¯-centers ≈10 ppm and of C-centers ≈ 45 ppm. A broad structureless superluminescence band with a maximum about 706 nm and a narrow band in the region of 705 to 720 nm were identified in the spectral range of 650–750 nm when excited by pulsed laser radiation at λ = 532 nm. It was found that the narrow-band superluminescence was not excited by pumping with continuous radiation at λ = 532 nm and the intensities of both types of superluminescence were summated under simultaneous pumping by continuous and pulsed radiation at λ = 532 nm. These data indicate either the different nature of the two types of superluminescence or that they belonged to NV¯ centers but with different excitation mechanisms. The existence of connection between the shape of the spectra of narrow-band superluminescence and of radiation pulses has been demonstrated. The observed features of narrow-band superluminescence are explained for the first time by the occurrence of mode-locking laser generation. The mode-locking laser generation without the use of reflective coatings on the sample or an external resonator on other laser materials has not been observed before.

S A Lebedev, V. A. Kizel, Boris Ya. Kogan

Temperature dependences of the direction of emission of superradiance and of the wavelength of stimulated emission were determined for a solution of rhodamine 6G in an internal reflection configuration. The results obtained were in good agreement with calculations. Some energy, spectral, and angular characteristics of the stimulated radiation were determined. It was also found that dye-activated polymer films could be used as the active media.

V. A. Gorshkov, Yu. N. Lukyanov, R. I. Sokolovskiǐ