Whole-field fluorescence lifetime imaging with picosecond resolution using ultrafast 10-kHz solid-state amplifier technology

We report the development of a high temporal resolution whole-field fluorescence lifetime imaging system based on an ultrafast solid-state laser system and a time-gated image intensifier operating at up to 10 kHz. The temporal instrument response is /spl sim/110 ps and we have imaged (environmentally perturbed) differences in fluorescence lifetime as small as 20 ps. Fluorophores exhibiting single- or double-exponential fluorescence decay profiles are routinely imaged and a near real-time update time of 3 s for the fluorescence lifetime map has been demonstrated using a modest personal computer. We also present provisional fluorescence lifetime images of tissue constituents. This fluorescence lifetime imaging technology is applicable to almost any optical instrument configuration and, when coupled with existing all-solid-state diode-pumped ultrafast laser technology, may yield a potentially inexpensive instrument for in vitro and in vivo biomedical imaging.