Phase modulated multiphoton microscopy

TL;DR

This paper introduces a phase modulation technique in multiphoton microscopy that enhances signal quality and enables multiplexing without complex detectors, applicable to various nonlinear microscopy methods.

Contribution

It presents a novel phase modulation approach for multiphoton microscopy that improves signal-to-noise ratio and facilitates multiplexed multi-focal scanning.

Findings

Phase modulation enhances two-photon fluorescence signal.

The technique enables multiplexing in frequency domain.

It simplifies multi-focal scanning without array detectors.

Abstract

We show that the modulation of the phases of the laser beams of ultra-short pulses leads to modulation of the two photon fluorescence intensity. The phase modulation technique when used in multi-photon microscopy can improve the signal to noise ratio. The technique can also be used in multiplexing the signals in the frequency domain in multi-focal raster scanning microscopy. As the technique avoids the use of array detectors as well as elaborate spatiotemporal multiplexing schemes it provides a convenient means to multi-focal scanning in axial direction. We show examples of such uses. Similar methodology can be used in other non-linear scanning microscopies, such as second or third harmonic generation microscopy.