Frequency response method of high speed spectrophotometry for luminescent materials

A frequency response method for high speed spectrophotometry, which is characterized by simpler instrumentation and narrower frequency bandwidth than the stroboscopic method, is developed from freuency domain considerations of a transient process. Time-resolved emission spectra of Y(2)O(2)S:Tb and Y(2)O(2)S:Eu show that Tb(3+) and Eu(3+) undergo two and three different types of transient processes, respectively. These processes are assigned to transitions from (5)D(j) to (7)F. Resolving power for time resolution is suggested as a new criterion for system evaluation and calculated for the frequency response and stroboscopic methods.