Temporally structured illumination for ultrafast time-stretch microscopy.

Area of Science:

• Optics and Photonics
• Measurement Science and Instrumentation
• Signal Processing

Background:

• Detector bandwidth limitations hinder ultrafast single-pixel measurements.
• Ultrafast imaging and spectroscopy demand higher frame rates and resolution.

Purpose of the Study:

• To develop a temporally structured illumination scheme to overcome detector bandwidth limitations.
• To enhance the capabilities of ultrafast single-pixel measurement techniques.

Main Methods:

• Inspired by structured illumination microscopy and space-time duality.
• Utilized an electro-optic modulator to impart a sinusoidal pattern onto time-stretch signals.
• Employed three measurements and reconstruction to effectively double detector bandwidth.

Main Results:

• Successfully captured high-frequency components beyond the original detector bandwidth.
• Applied the method to time-stretch microscopy, achieving ~4.0 μm spatial resolution.
• Acquired high-quality images at ~30 MHz frame rates using only half the detector bandwidth.

Conclusions:

• The developed method provides a simple, economical solution for high-speed signal acquisition.
• This technique surpasses resolution limits imposed by detector bandwidth in ultrafast measurements.
• Applicable to diverse fields including ultrafast imaging and single-shot spectroscopy.