Beyond intensity modulation: new approaches to pump-probe microscopy

TL;DR

This paper introduces innovative pump-probe microscopy methods that modulate pulse timing, polarization, or pulse length instead of intensity, enhancing imaging of heat-sensitive samples and enabling selective nonlinear interactions.

Contribution

It presents new pump-probe microscopy techniques that maintain constant beam intensity while modulating other parameters, offering advantages over traditional intensity modulation methods.

Findings

Improved image quality for heat-sensitive samples.

Selective addressing of nonlinear interactions.

Experimental validation of the proposed methods.

Abstract

Pump-probe microscopy is an emerging nonlinear imaging technique based on high repetition rate lasers and fast intensity modulation. Here we present new methods for pump-probe microscopy that keep the beam intensity constant and instead modulate the inter-pulse time delay, the relative polarization, or the pulse length. These techniques can improve image quality for samples that have poor heat dissipation or long-lived radiative states, and can selectively address nonlinear interactions in the sample. We experimentally demonstrate this approach and point out the advantages over conventional intensity modulation.