S0-S n two-photon absorption dynamics of rhodamine dyes

Abstract

The intensity-dependent transmission of picosecond ruby laser pulses of different duration through methanolic and ethanolic solutions of rhodamine B and rhodamine 6G is analysed. The transmission is affected by S 0 -S" two-photon absorption, by stimulated emission at the pumplaser frequency, by amplified spontaneous emission and by excited-state absorption. Various parameters involving the two-photon absorption dynamics are determined by comparing experiments with numerical simulations.

Investigation of nonlinear absorption and aggregation in aqueous solutions of rhodamine B using thermal lens technique

“…S1 --+ So internal conversion is negligible for RhB in the monomer form due to its high quantum yield and comparatively large energy separation between these levels. The possibility for the intersystem crossing to the triplet levels can also be ruled out, since the pulsewidth of the pump laser tp is ,-~ 9 ns in our work such that tp < < 1/kst where kst is the $1 ~ T1 intersystem crossing rate which is 1.7 x 106s -1 for RhB [10,11].…”

S0-S1 two photon absorption dynamics of organic dye solutions

“…The integrated level population $ [16]. The shorter T v6 is, the smaller the accumulation of population in level 6 (see [16]).…”

“…The two-photon absorption cross-sections of dye molecules were measured previously by fluorescence analysis [9][10][11][12][13][14][15]. In a recent paper [16] the S 0 -S" (n ^ 2) two-photon absorption dynamics of rhodamine dyes was studied by transmission measurements and theoretical simulations.…”

Intra-cavity pulse compression in passively mode-locked Nd-glass lasers

“…The decorrelation procedure is described in ref. [33]. The pulse at position A near the pulse train maximum has the shape of a single pulse of 6.2 ps duration.…”

“…Other configurations (two-plate birefringent filter with one saturable absorber, one-plate birefringent filter with one or two saturable absorbers) have been analysed and the results are summarized in table 1. If only one birefringent filter and one saturable absorber is used (cell DC2 filled with solvent 1,2-dichloroethane), a leading side pulse often remains besides the central and trailing pulse (twophoton fluorescence traces with 5 peaks at r = ±2f p , ±/p and 0) [33]. The use of a one-plate birefringent filter together with two dye cells results in the generation of shorter central pulses with somewhat higher trailing side pulses compared to the two-plate filter situation.…”