Super-resolution Reflection Microscopy via Absorbance Modulation

Parul Jain; Claudia Geisler; Dennis Leitz; Viktor Udachin; Sven Nagorny; Thea Weingartz; Jörg Adams; Andreas Schmidt; Christian Rembe; Alexander Egner

doi:10.1021/acsnanoscienceau.3c00013

Super-resolution Reflection Microscopy via Absorbance Modulation

ACS Nanosci Au. 2023 Jun 14;3(5):375-380. doi: 10.1021/acsnanoscienceau.3c00013. eCollection 2023 Oct 18.

Authors

Affiliations

¹ Department of Optical Nanoscopy, Institute for Nanophotonics Göttingen e.V., 37077 Göttingen, Germany.
² Institute of Electrical Information Technology, Clausthal University of Technology, 38678 Clausthal-Zellerfeld, Germany.
³ Clausthal Center of Materials Technology, Clausthal University of Technology, 38678 Clausthal-Zellerfeld, Germany.
⁴ Institute of Organic Chemistry, Clausthal University of Technology, 38678 Clausthal-Zellerfeld, Germany.
⁵ Institute of Physical Chemistry, Clausthal University of Technology, 38678 Clausthal-Zellerfeld, Germany.

Abstract

In recent years, fluorescence microscopy has been revolutionized. Reversible switching of fluorophores has enabled circumventing the limits imposed by diffraction. Thus, resolution down to the molecular scale became possible. However, to the best of our knowledge, the application of the principles underlying super-resolution fluorescence microscopy to reflection microscopy has not been experimentally demonstrated. Here, we present the first evidence that this is indeed possible. A layer of photochromic molecules referred to as the absorbance modulation layer (AML) is applied to a sample under investigation. The AML-coated sample is then sequentially illuminated with a one-dimensional (1D) focal intensity distribution (similar to the transverse laser mode TEM01) at wavelength λ₁ = 325 nm to create a subwavelength aperture within the AML, followed by illumination with a Gaussian focal spot at λ₂ = 633 nm for high-resolution imaging. Using this method, called absorbance modulation imaging (AMI) in reflection, we demonstrate a 2.4-fold resolution enhancement over the diffraction limit for a numerical aperture (NA) of 0.65 and wavelength (λ) of 633 nm.