S1-S0 relaxation time of saturable absorber DDI

Abstract

The saturable dye DDI is excited with picosecond ruby laser pulses to the S\ singlet state and the relaxation to the ground state So is determined by measuring the transmission of the exciting pulses through the sample. The relaxation time is found to be r -17 ± 3 ps for DDI dissolved in methanol. Admictures of rhodamine 6G, potassium iodide, or tetrabutylammonium iodide do not change the decay time.

Pulse compression in a passively mode-locked ruby laser

“…The compression of the chirped pulses by the finite spectral gain width of the active medium results in efficient pulse shortening in the trailing part of the pulse train. The reported strongly varying pulse durations of different experimental groups [1][2][3][4][5][6][7][8] may be understood by the above described mechanisms.…”

“…The curve is fitted to 31 ps at pulse number 0 and remains constant along the train. The peak pulse intensity in the contacted dye cell [/ 0L -e(r = 0)/At L =* 2 X10 9 W/cm 2 already for pulse number 0] is far above the saturation intensity of the dye I s = hv L /o L T -2.2 X10 7 W/cm 2 (absorption cross section a L = 7.6 X 10~1 6 cm 2 , absorption recovery time r = 17 ps [4]) and therefore no pulse shortening by the saturable dye occurs.…”

Solvent effect on the spectral properties of dipolar laser dyes: Evaluation of ground and excited state dipole moments

“…Note that,   * bands show a red shift in the solvents of increasing polarity while n  * bands show a blue shift. The solvatochromic shifts have also been used for the determination of the excited state dipole moments of some dyes [28][29][30][31][32][33].…”

A versatile dye-laser generator-amplifier system for intense, tunable picosecond pulse generation

“…The detectors were aperture to accept a divergence angle ofJ0 = 2xlO -3 rad (solid Table 1 (5) is G m |^8 x 10 4 for <7em = 7.5 x 10" 1 6 cm 2 ( Fig. 2), <r ex>F = 5 x 10" 17 cm 2 , and <x ex , L = 5 x 10" 17 cm 2 [28]. The dye amplifier chain increases the output pulse signal up to an energy conversion of W F /W L ~ 0.09 after the third amplifier cell (Fig.…”