Abstract

A spectroscopic setup that enables the mapping of absorption and photoluminescence with submicrometer spatial resolution and high sensitivity is described. A photothermal heterodyne imaging pump/probe technique is employed for absorption mapping, and low-signal, spatially resolved photoluminescence is recorded using photon counting. High-spatial-resolution mapping is accomplished by using high-numerical-aperture microscope objective focusing laser beams (pump and probe) into a submicrometer spot and raster-scanning sample mounted on the nanopositioning translation stage. Performance of the setup is illustrated by mapping absorption and luminescence of the hafnium oxide film with embedded hafnium nanoparticles and multilayer dielectric grating. In both cases, submicrometer spatial resolution is demonstrated, and possible physical mechanisms leading to image contrast on a submicrometer scale are discussed.

© 2019 Optical Society of America

Submicrometer resolution images of absorbance and thermal diffusivity with the photothermal microscope

Dean S. Burgi and Norman J. Dovichi
Appl. Opt. 26(21) 4665-4669 (1987)

Simultaneous absorption, scattering, and luminescence mappings for the characterization of optical coatings and surfaces

Laurent Gallais and Mireille Commandré
Appl. Opt. 45(7) 1416-1424 (2006)

Phase-sensitive lock-in detection for high-contrast mid-infrared photothermal imaging with sub-diffraction limited resolution

Panagis D. Samolis and Michelle Y. Sander
Opt. Express 27(3) 2643-2655 (2019)

Photothermal microspectroscopy with Bessel–Gauss beams and reflective objectives

Maryam Zahedian, Eun Sohl Koh, and Bogdan Dragnea
Appl. Opt. 58(27) 7352-7358 (2019)

Characterization of absorptance homogeneity in thin-film coatings for high-power lasers by thermal lensing microscopy

Facundo Zaldivar Escola, Nélida Míngolo, Oscar E. Martínez, Jorge J. Rocca, and Carmen S. Menoni
Appl. Opt. 58(26) 7233-7240 (2019)