Photons emitted from a sample responsive to being excited by laser pulses are directed through a prism onto a photomultiplier tube having several spaced-apart anodes. The prism alters the path of each photon as a function of its wavelength so that the wavelength determines the anode to which the photon is directed. Taps of first and second delay lines that are coupled to respective alternating anodes. When an anode receives the photon, it generates a pulse that propagates through the delay line in opposite directions from its associated tap. A timer determines first and second times from the laser pulse to the pulse reaching the first and second ends of the delay line. The difference between the first and second times corresponds to the wavelength of the emitted photon and the sum of the first and second times corresponds to the emission delay of the emitted photon.