Time multiplexing and parallelization in multifocal multiphoton microscopy

We investigate the imaging properties of high-aperture multifocal multiphot on microscopy on the basis of diffraction theory. Particular emphasis is pl aced on the relationship between the sectioning property and the distance b etween individual foci. Our results establish a relationship between the de gree of parallelization and the axial resolution for both two- and three-ph oton excitation. In addition, we show quantitatively that if a matrix of te mporal delays is inserted between the individual foci, it is, for the first time to our knowledge, possible to solve the classical conflict between th e light budget and the sectioning property in three-dimensional microscopy and to provide a virtually unlimited density of foci at best axial resoluti on. (C) 2000 Optical Society of America [S0740-3232(00)01906-2] OCIS codes: 180.6900, 350.5730, 320.7080, 350.2950, 180.1790, 190.4180.