Short-time Fourier transform laser Doppler holography

TL;DR

This paper demonstrates high-speed laser Doppler holography using a CMOS sensor, enabling wide-field optical fluctuation imaging at 250 Hz and real-time video rendering, validated through vibrometry experiments.

Contribution

It introduces a method for high-rate laser Doppler holography with real-time imaging and tunable measurement bands using off-the-shelf hardware.

Findings

Achieved 250 Hz hologram acquisition rate on 1 Megapixel CMOS sensor.

Enabled real-time, wide-field optical fluctuation imaging with tunable frequency bands.

Validated the technique with a non-contact vibrometry experiment.

Abstract

We report a demonstration of laser Doppler holography at a sustained acquisition rate of 250 Hz on a 1 Megapixel complementary metal-oxide-semiconductor (CMOS) sensor array and image display at 10 Hz frame rate. The holograms are optically acquired in off-axis configuration, with a frequency-shifted reference beam. Wide-field imaging of optical fluctuations in a 250 Hz frequency band is achieved by turning time-domain samplings to the dual domain via short-time temporal Fourier transformation. The measurement band can be positioned freely within the low radio-frequency spectrum by tuning the frequency of the reference beam in real-time. Video-rate image rendering is achieved by streamline image processing with commodity computer graphics hardware. This experimental scheme is validated by a non-contact vibrometry experiment.