OPTICAL DESIGN CONSIDERATIONS AND PERFORMANCE OF A SPECTRO-STREAK APPARATUS FOR TIME-RESOLVED FLUORESCENCE SPECTROSCOPY

A time-resolved spectral photometer, i.e., an instrument for simultane ously measuring intensity, time, and wavelength (I-t-lambda) is descri bed. The ''spectro-streak'' apparatus comprises a grating objective co upled to a commercial streak camera with 2-ps resolution, a channel pl ate amplifier, a CCD camera, and a computer for data processing. The n ecessary calibration and correction procedures are discussed in detail ; these are sweep nonlinearity correction, shading correction, geometr ic distortion correction, wavelength calibration, spectral intensity c orrection, and dispersion correction. The performance of the instrumen t is demonstrated with an example of current interest, the measurement of the solvatochromic dynamic Stokes shift of fluorescence from a cha rge-transfer system in solution.