Rhodamine 6G dye laser

Figure 1.19 Energy levels and transitions in the rhodamine 6G dye laser...

The experimental arrangement is basically similar to that of Hansch et al. (4). A Spectra Physics Ar+ laser operating at 514.5 nm pumps a Rhodamine 6G dye laser tuned with a birefrin-gent filter. The linewidth is 25 to 30 GHz, and the wavelength is tuned between 585.0 nm and 585.2 nm. The output mirror has a 1 meter radius of curvature and a reflectivity of 98% at 585.0 nm. The dye laser cavity is 74 cm long, and the laser is always run TEMoo (this sometimes necessitates the use of an intracavity aperture). 

Fig. 20. Schematic diagram of the Synchroscan streak camera system. A Spectra Physics model 164 acousto-optically mode-locked argon ion laser modulated at 69.44MHz pumps the Rhodamine 6G dye laser formed by mirrors Mi, M2, M3 and M4. This dye laser typically produces pulses of 2 ps duration with an energy content of 0.6 nJ. The second harmonic is generated intracavity in an ADP crystal. The UV radiation is then coupled out through mirror Ms and a filter F2 is used to eliminate any transmitted visible light before focusing into the sample cell with lens Lt. The fluorescence is detected at 90 to the incident beam. A lens L2 collects the fluorescence which passes through a polarizer and a bandpass filter and then onto the slit of the streak camera. (After ref. 69.)...

Time resolved hole burning spectra were measured by means of a femtosecond transient absorption spectrometer system. A second harmonics of a mode locked cw Nd + YAG laser (Quantronix, 82MHz) was used for a pumping source. A synchronously pumped rhodamine 6G dye laser with a saturable absorber dye jet (DODCl/DQOCI) and dispersion compensating prisms in the cavity was used. The output of the dye laser (lOOfs fwhm, 600pJ/pulse) was... 

Fluorescence lifetimes were measured by time-correlated single photon counting using a mode-locked, synchronously pumped, cavity-dumped pyridine I dye laser (343 nm) or Rhodamine 6G dye laser (290 nm). Emissive photons were collected at 90° with respect to the excitation beam and passed through a monochromator to a Hamamatsu Model R2809U microchannel plate. Data analysis was made after deconvolution (18) of the instrument response function (FWHM 80 ps). 

It is of interest to understand how multiphoton excitation is accomplished. The S70-nm excitation was obtained from the cavity-dumped pulses from a rhodamine 6G dye laser. These pulses ate about 7 ps wide. Excitation at 8SS nm was accomidished using pulses from a Tcsapphire laser, which ate about 70 fs wide. Pulsed excitation is used because it is necesstny to have a high instantaneous density of photons in orda- to have a agmficant probability of MPE... 

The difficult in resolving (he two intensity decay components is illustrated by the intensity decay of tryptophan at pH 7 (Figure 17.4). The light source was a cavity-dumped rhodamine 6G dye laser, which was frequency-doubled to 29S nm and provided pulses about 7 ps wide. The detector was an MCP PMT detector. This confign-ration of high-speed components represents the state of the art for TCSPC measurements. The data were fit to the single- and double-exponential models,... 

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