Related Experiment Video
Updated: Aug 8, 2026

Simultaneous Label-Free Autofluorescence Multi-Harmonic Microscopy
Published on: August 29, 2025
Effect of pulse duration on two-photon excited fluorescence and second harmonic generation in nonlinear optical
Abstract:
We have developed a multiphoton microscopy (MPM) system using a 12-fs Ti:sapphire laser with adjustable dispersion precompensation in order to examine the impact of pulse duration on nonlinear optical signals. The efficiencies of two-photon-excited fluorescence (TPEF) and second harmonic generation (SHG) were studied for various pulse durations, measured at the sample, ranging from approximately 400 fs to sub-20 fs. Both TPEF and SHG increased proportionally to the inverse of the pulse duration for the entire tested range. Because of improved signal-to-noise ratio, sub-20-fs pulses were used to enhance MPM imaging depth by approximately 160%, compared to 120-fs pulses, in human skin.
Related Concept Videos
Super-resolution Fluorescence Microscopy
NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences
Fluorescence and Phosphorescence: Instrumentation
