Laser induced fluorescence experimental arrangement

Figure 18. Experimental arrangement used in the author s laboratory to measure laser-induced fluorescence signals from flame species...

Figure 1. Schematic diagram of the experimental arrangements for laser absorption and laser-induced fluorescence. (Reproduced with permission from Ref. 7 Copyright 1983, J. Chem. Phys.)...

First, are shown absorption and fluorescence spectra in Fig. 13 of a portion of the 7-0 Lyman band of Ha obtained by Marinero et al. [30] using the experimental arrangement given in Fig. 11. As shown by the lower trace taken at 1/10 the pressure of that for the absorption spectrum (upper trace), detection by laser-induced fluorescence is clearly a far more sensitive technique. 

With an iodine cell inside the resonator of a cw multimode dye laser, an enhancement factor of g = 10 could be achieved, allowing the detection of I2 molecules at concentrations down to n < 10 /cm [20]. This corresponds to a sensitivity limit of aL < 10 . Instead of the laser output power, the laser-induced fluorescence from a second iodine cell outside the laser resonator was monitored as a function of wavelength. This experimental arrangement (Fig. 1.16) allows demonstration of the isotope-specific absorption. When the laser beam passes through two external iodine cells filled with the isotopes l2 and l2, tiny traces of l2 inside the laser cavity are sufficient to completely quench the laser-induced fluorescence from the external l2 cell, while the l2 fluorescence is not affected [21]. This demonstrates that those modes of the broadband dye laser that are absorbed by the internal l2 are completely suppressed. 

Fig. 1.51 Laser-induced fluorescence (a) level scheme and (b) experimental arrangement for measuring LIF spectra...

The experimental arrangement for such femtosecond experiments is exhibited in Fig. 10.14. The output pulses from a femtosecond pulse laser (Sect. 6.1.5) are focused by the same lens into the molecular beam. The probe pulses are sent through a variable optical-delay line and the absorption a (At) of the probe pulse as a function of the delay time At is monitored via the laser-induced fluorescence. Cutoff Alters suppress scattered laser light. 

Fig.4.49a,b. Combination of F.P.I. and spectrograph for high-resolution spectroscopy of laser-induced fluorescence, (a) Imaging of the ring system onto the entrance slit of the spectrograph, (b) Experimental arrangement... 

Fig. 8.19. (a) Experimental arrangement for combination of laser-induced fluorescence and photoexcitation spectroscopy, (b) Excitation spectrum o the a2tt3/2(0,0,0) x2ri3/2(l 0,0) band of HBO2 at 579 nm. The numbering... 

A typical experimental arrangement for measuring RF transitions between Zee-man levels in the upper state of the optical transition is shown in Fig. 5.8. A coil around the sample cell provides the RF field, while the dc magnetic field is produced by a pair of Helmholtz coils. The fluorescence induced by a polarized dye laser beam is monitored by a photomultiplier through a polarizer as a function of the radio frequency co f [514]. 

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