FAST AMPLIFYING OPTICAL KERR GATE USING STIMULATED-EMISSION OF ORGANIC NONLINEAR DYES

We describe a ''fast'' optical Kerr gate (OKG) which can act at the sa me time as light amplifier. As a Kerr medium we used different laser d yes (Cresyl violet, Nile blue, Rhodamine 640). The most efficient at a vailable wavelengths (595 nm and 297 nm) was Cresyl violet dissolved i n methanol. With a classical OKG arrangement we obtained a maximum tra nsmission of 4000% at 650 nm (strong amplification of the transmitted signal), this wavelength corresponding to a gain maximum of Cresyl vio let. The opening time of the OKG was 15 ps limited by the reorientatio n time of the dye molecule in methanol solvent. With a special OKG arr angement based on the use of two delayed opening pulses, we obtained 2 40% transmission at the same wavelength with an opening time of 2.5 ps . Possible improvements of the method are described.