Generalized spectral phase-only time-domain ptychographic phase reconstruction applied in nonlinear microscopy

TL;DR

This paper introduces I$^2$PIE, a novel spectral phase control method based on time-domain ptychography, which improves pulse compression and image quality in nonlinear microscopy applications like SHG and TPEF.

Contribution

The paper presents the first application of spectral phase control via time-domain ptychography in nonlinear microscopy, enhancing image contrast and signal-to-noise ratio.

Findings

Improved contrast in nonlinear microscopy images.

Enhanced signal-to-noise ratios with I$^2$PIE.

Successful demonstration in biological samples.

Abstract

Nonlinear microscopy has evolved over the last few decades to become a powerful tool for imaging and spectroscopic applications in biological sciences. In this study, I$^2$PIE, a novel spectral phase control technique, was implemented in order to compress broad-bandwidth supercontinuum light pulses generated in an all-normal-dispersion (ANDi) photonic crystal fiber (PCF). The technique, based on time-domain ptychography, is demonstrated here in a nonlinear microscopy application for the first time, to the best of our knowledge. The first real-world application of this technique for second-harmonic generation and two-photon excitation fluorescence microscopies in biological samples is presented. We further show that in our implementation, I$^2$PIE leads to improved contrast and signal-to-noise ratios in the generated images, compared to conventional compression techniques used in nonlinear microscopy.