Photon budget analysis for a novel fluorescence lifetime imaging microscopy system with a modulated electron-multiplied all-solid-state camera

In this paper, a novel fluorescence lifetime imaging microscopy system is proposed that uses a modulated, electron-multiplied, all-solid-state camera (MEM-FLIM). This camera will eliminate the need for an image intensifier through the use of an application-specific charge coupled device (CCD) design. We are designing and building a CCD image sensor that can be modulated at the pixel level and that will have an electron multiplication feature to provide high sensitivity at low-light levels. The proposed design has advantages such as better signal-to-noise ratio (SNR), less geometric distortion, better resolution and low cost. It will be employed in both fluorescence lifetime imaging microscopy (FLIM) and, hopefully, in other biological and medical applications. We describe here the characteristic of our system and present a photon budget analysis for MEM-FLIM. This photon budget is important in order to understand the constraints which will be encountered in design and fabrication of our system.