Three-dimensional spatiotemporal focusing of holographic patterns.

Oscar Hernandez,Valentina Emiliani,Dimitrii Tanese,Eirini Papagiakoumou,Claire Wyart,Kevin Fidelin

doi:10.1038/ncomms11928

Abstract

Two-photon excitation with temporally focused pulses can be combined with phase-modulation approaches, such as computer-generated holography and generalized phase contrast, to efficiently distribute light into two-dimensional, axially confined, user-defined shapes. Adding lens-phase modulations to 2D-phase holograms enables remote axial pattern displacement as well as simultaneous pattern generation in multiple distinct planes. However, the axial confinement linearly degrades with lateral shape area in previous reports where axially shifted holographic shapes were not temporally focused. Here we report an optical system using two spatial light modulators to independently control transverse- and axial-target light distribution. This approach enables simultaneous axial translation of single or multiple spatiotemporally focused patterns across the sample volume while achieving the axial confinement of temporal focusing. We use the system's capability to photoconvert tens of Kaede-expressing neurons with single-cell resolution in live zebrafish larvae.

Highlights

Two-photon excitation with temporally focused pulses can be combined with phasemodulation approaches, such as computer-generated holography and generalized phase contrast, to efficiently distribute light into two-dimensional, axially confined, user-defined shapes
As a more flexible way to elaborate light patterning, phasemodulation approaches using liquid-crystal spatial light modulators, such as computer-generated holography (CGH)[20,21] and generalized phase contrast (GPC)[22] have demonstrated efficient light sculpting in two-dimensional (2D) user-defined shapes
The phase holograms addressed on SLM1 were calculated using a Gerchberg and Saxton (GS)-based algorithm[33]

Summary

Introduction

Two-photon excitation with temporally focused pulses can be combined with phasemodulation approaches, such as computer-generated holography and generalized phase contrast, to efficiently distribute light into two-dimensional, axially confined, user-defined shapes. A first SLM laterally shapes the target light distribution that is focused on the TF grating, while a second SLM, positioned after the grating, controls the axial position(s) of the spatiotemporal focal plane(s) in the sample volume.

Results

Conclusion