Subnanosecond single photon timing measurements using a pulsed diode-laser.

The convenient and inexpensive use of a pulsed diode-laser (Hamamatsu Photonics PLP-01 660 nm) is demonstrated as a low cost alternative to a standard pulsed laser or gas discharge flash system in a commercial time-correlated single photon counting instrument. Fluorescence lifetimes of compounds of photobiological interest such as phytochrome, chlorophyll a, 1,1'-diethyl-4,4' carbocyanine iodide (DCI/cryptocyanin),5,10,15,20-tetra(p-phenyl) porphyrin and stentorin I are presented using the pulsed diode-laser source.