Thousand foci coherent anti-Stokes Raman scattering microscopy

Abstract

We demonstrate coherent anti-Stokes Raman scattering (CARS) microscopy with 1089 foci, enabled by a high repetition rate amplified oscillator and an optical parametric amplifier. We employ a camera as a multichannel detector to acquire and separate the signals from the foci, rather than using the camera image itself. This allows us to retain the insensitivity of the imaging to scattering afforded by the non-linear excitation point-spread function, which is the hallmark of point-scanning techniques. We show frame rates of 0.3 Hz for a megapixel CARS image, limited by the camera used. The laser source and corresponding CARS signal allows for at least 1000 times higher speed, and using faster cameras would allow acquiring at that speed, opening a perspective to megapixel CARS imaging with a frame rate of more than 100 Hz.