Effect of coherence of generating radiations on optical parametric up-conversion

Pavel Chmela

Pavel Chmela

Pavel Chmela

Yu A Galaĭchuk, V. L. Strizhevskiǐ, Yu. N. Yashkir

A fluctuation theory is developed for the parametric conversion of infrared radiation utilizing four-photon difference frequency generation processes. An analysis is made of some features of optical parametric oscillation in this system allowing for sum frequency generation. Parametric "conversion" of quantum fluctuations to the frequency range of the infrared signal is discussed and it is shown that this effect increases the noise level.

Vladimir V. Kornienko, Kirill A. Kuznetsov, A.A. Leontyev +2 more

Quantum effect of parametric down-conversion is studied in a strongly frequency non-degenerate regime, when pairs of correlated optical and terahertz photons are generated along with parametric amplification and frequency conversion of thermal fluctuations and external radiation at terahertz frequencies. The terahertz photon fluxes emitted due to parametric down-conversion are registered. Direct incoherent nonlinear-optical detection is demonstrated for continuous wave sources at 0.2-0.4 THz.

M. M. Fejer

The colored rings shown in figure 1 are a spectacular manifestation of one type of nonlinear optical frequency conversion: parametric amplification of quantum noise. The amplification in this case is produced by the propagation of an intense pulse of ultraviolet radiation through a crystal of barium borate. When intense electromagnetic radiation propagates through such a material, whose polarization response at optical frequencies manifests a strongly nonlinear dependence on electric field amplitude, nonlinear mixing of the input radiation generates new spectral components. We can exploit this phenomenon to generate coherent radiation at frequencies for which we have no convenient laser sources.