Sliced fluorescence imaging: a versatile method to study photo-induced dynamic processes

Abstract

To reduce the image blurring which originates from contributions of a cylindrical array of photolysis events in a photo-induced experiment, a variant of fluorescence imaging techniques has been developed to study photodissociation dynamics and collisional relaxation processes in the bulk. The experimental arrangement utilizes sliced imaging techniques of photofragments by the laser-induced fluorescence detection scheme. An unconventional procedure is employed to guide the photolysis laser in the viewing direction of the imaging detector with an appropriate obstruction. The sliced image in the direction perpendicular to the photolysis laser is equivalent to a two-dimensional projection of the fluorescence image of photoproducts from a single photolysis center. Experimental images of state-selected CN photofragments from the ICN photodissociation are presented to illustrate the versatility of the present method.

Three-dimensional sliced fluorescence imaging in bulbs

“…For dynamic studies in bulbs, double resonance [10][11][12][13][14][15][16] and Doppler 17 spectroscopic detection schemes, which exhibit advantages in state preparations, have been successfully employed to access their state-to-state integrated or differential cross sections. 3DSFI combines the sliced fluorescence imaging techniques 18 and a double resonance spectroscopic detection scheme 19 to acquire the central slice of state-selected Newton spheres of scattering products. The present experimental technique aims at dynamic studies of molecular photodissociation processes and photoinitiated inelastic and reactive collisions in a bulb environment.…”

“…The 3DSFI experimental apparatus is quite similar to the sliced fluorescence imaging experiment, 18 where its detailed procedures have been published previously. The 3DSFI experimental apparatus is quite similar to the sliced fluorescence imaging experiment, 18 where its detailed procedures have been published previously.…”

“…For other technical details, experimental procedures in the sliced fluorescence imaging study 18 should be consulted and will not be repeated. The first probe laser pulse, which overlapped the 266 nm laser beam spatially and temporally, was a Nd:YAG laser ͑LOTIS TII, LS-2137U͒ pumped dye laser system ͑Pulsare Excellent, Fine Adjustment͒.…”

“…21,22 After the confirmation of consistency, the B − A excitation spectrum of CN from a chosen quantum state in the A 2 ⌸ manifold was obtained. 18 The corresponding spectroscopic assignments of their double resonance transitions are given in the right panel of Fig. Representative images are presented in Fig.…”

Sliced Fluorescence Imaging Techniques for the Study of Photo‐initiated Dynamic Processes in Bulbs

“…An unconventional experimental arrangement which overcomes the blurring difficulty in fluorescence imaging experiments has been implemented. 17 Our results are briefly reviewed in the next section. To push the envelope further, we developed a three-dimensional sliced fluorescence imaging method, 18 which should be suitable in the study of state-to-state inelastic collisions and photo-initiated reactive scatterings in bulbs.…”