Analysis of fast axial scanning scheme using temporal focusing with acousto-optic deflectors

Abstract

2009) Analysis of fast axial scanning scheme using temporal focusing with acousto-optic deflectors, Journal of Modern Optics, 56:1, 81-84, Multiphoton microscopy has gained broad application in biology and medicine in the recent decade by assessing biological structure and function with high spatial resolution. Recently it has achieved fast two-dimensional x-y imaging by using inertia-free scanning mechanisms. However, the axial scanning speed is severely limited by mechanical inertia. This paper proposes a fast axial scanning scheme using temporal focusing implemented with an inertia-free scanning device, such as an acousto-optic device (AOD), and presents an experimental demonstration of two-photon axial scanning over a 9 mm range using AODs operated from 80 to 120 MHz. A theoretical analysis provides the detailed characteristics of this method. The effects of both the ratio of collimating lens to objective lens focal lengths or magnification (M), and the degree of group delay dispersion (GDD) in the light source on the temporal focusing and axial scanning range are described by theory and experiments.

Three-dimensional spatiotemporal focusing of holographic patterns

“…Alternative solutions for axial displacement of a temporally focused shape used either variable group velocity dispersion (GVD) 38 52 53 54 55 or mechanical axial translation of the TF grating 35 . Indeed, introducing variable GVD to the input laser pulse enabled efficient axial displacement of a Gaussian beam's temporal focal plane.…”

Scanless two-photon excitation with temporal focusing

“…3c) 5,6 . Alternative variations of TF use two parallel gratings 51,52 , or a digital micromirror device (DMD) as the dispersive element 53,54 .…”

Optical developments for optogenetics

“…Pre-chirping the frequencies results in recombination of the spectral components at a plane offset from the nominal objective focal plane (Durst et al, 2006). This phenomenon has been experimentally realised by chirping the beam with a pair of prisms (Durst et al, 2006(Durst et al, , 2008, remotely with a pair of AODs (Du et al, 2009), a folded grating pair and a piezo-bimorph mirror (Straub et al, 2011) or by replacing the standard TF diffraction grating with a dual-prism grating (DPGrism) composed of two prisms and a transmission diffraction grating (Dana and Shoham, 2012b). Lastly, we can achieve more flexible control of the laser pulse shape by modulating the spectral phase with an SLM at the Fourier plane of the TF telescope (Suchowski et al, 2006).…”