Photoacoustic microscopy with meta-optics

TL;DR

This paper demonstrates the use of meta-optics, specifically metalenses, to replace traditional optical elements in photoacoustic microscopy, resulting in more compact, multifunctional, and deeper imaging capabilities through simulations and experiments.

Contribution

It introduces the integration of metalenses into photoacoustic microscopy, replacing bulky glass optics and enhancing depth of field, validated through simulations and experimental comparisons.

Findings

Meta-optics can replace conventional optical elements in photoacoustic microscopy.

Metalenses increase the depth of field in imaging systems.

Experimental results confirm the advantages of meta-optics over traditional lenses.

Abstract

Recent advances in the miniaturization of optical elements have led to the emergence of novel imaging systems, used for industrial and consumer-based applications. The underlying methods are particularly prevalent in the realms of medical imaging and optical microscopy. Avoiding bulky optical elements can be extremely beneficial to many microscopy modalities, one of which is photoacoustic microscopy. Relying on short, highly focused light pulses that need to be precisely controlled, large and heavy optical elements can often hinder the overall performance of such systems. We propose the utilization of increasingly popular optical elements, so-called meta-optics, in the excitation path of a photoacoustic microscope. The metalenses, which were designed and used for this work, consist of sub-wavelength elements that enable elaborate phase control of incident light and multifunctionality within a single optical element. This allowed us to not only replace common optical elements in the excitation path of the photoacoustic microscope, completely omitting any conventional glass elements, but also to design an adapted lens, increasing the depth of field. With our work, we prove the benefit of meta-optics for photoacoustic microscopy by comparing two different metalenses to a conventional glass lens in simulations as well as experiments. We expect this to be a step into the direction of more advanced meta-optics being utilized in photoacoustic imaging setups.