# Transient vibration imaging with time-resolved synthetic holographic confocal microscopy

## TL;DR

This paper presents a novel confocal microscopy technique using synthetic holography for high-resolution, time-resolved vibration imaging capable of capturing transient dynamics at nanosecond scales.

## Contribution

The authors introduce a new method for dynamic phase imaging that enables direct time-domain recording of transient vibrations with high temporal and spatial resolution.

## Key findings

- Achieved 100 ns time resolution in vibration imaging.
- Demonstrated sub-picometer vertical sensitivity.
- Captured frequency and mode profiles of vibrations.

## Abstract

We introduce a new modality for dynamic phase imaging in confocal microscopy based on synthetic optical holography. By temporal demultiplexing of the detector signal into a series of holograms, we record time-resolved phase images directly in the time domain at a bandwidth as determined by the photo detector and digitizer. We demonstrate our method by optical imaging of transient vibrations in an atomic force microscope cantilever with 100 ns time resolution, and observe the dynamic deformation of the cantilever surface after excitation with broadband mechanical pulses. Temporal Fourier transform of a single data set acquired in 4.2 minutes yields frequency and mode profile of all excited out-of-plane vibration modes with sub-picometer vertical sensitivity and sub-micrometer lateral resolution. Our method has the potential for transient and spectroscopic vibration imaging of micromechanical systems at nano- and picosecond scale time resolution.