Small footprint SLIDE demonstrator for 40Hz volume rate multiphoton microscopy

The recently developed SLIDE microscope enables rapid imaging in nonlinear two-photon microscopy, where frame rates of 4 kHz are achieved. Such fast acquisition speeds coupled with the molecular specificity of fluorescence markers and the high optical resolution in the sub-μm range allow volume scan rates at 40 Hz. A commercially available Fourier Domain Mode Locked Laser system (Optores GmbH, Munich, Germany) was used as the light source emitting at 1060 nm (Bandwidth 15 nm). An electro-optical Modulator (EOM) splits the light of a single sweep duration up into 600 pulses with 30 ps pulse duration each. Each of it is then spatial separated by a diffractive grating. Only one scanner is needed for beam steering to excite the slow axis resulting to a frame rate of 4 kHz. Using a piezo driver for the objective of the microscope at a frequency of 20 Hz, a live 4D volume scan of 40 Hz with 600 x 400 x 100 voxel is possible. Until now, SLIDE systems were bulky and bound onto a fixed optical desk. The Medical Laser Centre Lübeck developed a transportable and reliable SLIDE system, so that this new and highly innovative technology can be made available to various biological laboratories in Europe. This work was conducted in the framework of the EU project “Faircharm.”