Quasi-simultaneous multi-focus imaging using a lock-in pixel image sensor and TAG lens.

Area of Science:

• Optics and Photonics
• Imaging Technology

Background:

• Traditional imaging techniques are limited by a shallow depth of field (DOF), restricting the ability to capture high-resolution images of objects with significant depth.
• Acquiring multiple focal planes typically requires multiple shots or complex post-processing, which can be time-consuming and may introduce artifacts.

Purpose of the Study:

• To introduce and validate a novel quasi-simultaneous multi-focus imaging technique called simulfocus imaging.
• To enable high-resolution imaging of entire objects distributed along the depth direction in a single exposure.

Main Methods:

• Simulfocus imaging synchronizes a tunable acoustic gradient index (TAG) lens, capable of rapid focal adjustments (tens to hundreds of kHz), with a lock-in pixel image sensor.
• The lock-in pixel image sensor allows multiple exposures at precise timings within a single shot by utilizing multiple photoelectron storage units per pixel.
• By assigning specific exposure timings synchronized with the TAG lens's focus fluctuations, multiple focal planes are captured simultaneously.

Main Results:

• The simulfocus imaging technique successfully acquired multiple focal planes in a single shot.
• Experimental validation in both microscope and telescope configurations demonstrated the effectiveness of the technique.
• High-resolution imaging of objects extending beyond the conventional depth of field was achieved.

Conclusions:

• Simulfocus imaging offers a robust solution for capturing extended depth information in a single shot.
• The technique's versatility is confirmed by its successful application in diverse optical setups like microscopes and telescopes.
• This advancement provides a powerful tool for applications requiring rapid, high-resolution 3D imaging.