APPLICATION OF CW-LASER DIODES FOR THE DETERMINATION OF FLUORESCENCE LIFETIMES

Continuous wave laser diodes in the visible region can be used for the determination of fluorescence lifetimes using the phase fluorometric method. With moderate frequencies between 10 and 50 MHz and very high modulation in the excitation light a time resolution of less than 0.1 ns is possible. The method was applied for two laser dyes, nile blue a nd oxazine-4, and shows good agreement to known values. The main prati cal advantage is that any changes of the light intensity in the whole apparatus don't influence the results. Due to the low power consumptio n of the light source this new method can be used for fluorescence sen sor applications.