2020/06/03 by Lauren E. Barr, Peter Karlsen, Barr, Lauren E. +14
Biochemistry, Genetics and Molecular Biology · Engineering · Physics and Astronomy · #Advanced Fluorescence Microscopy Techniques #Applied Physics (physics.app-ph) #FOS: Physical sciences #Instrumentation and Detectors (physics.ins-det) #Near-Field Optical Microscopy #Optics (physics.optics) #Spectroscopy Techniques in Biomedical and Chemical Research #Terahertz technology and applications #physics.app-ph #physics.ins-det #physics.optics
paper · pdf · doi:10.48550/arxiv.2006.02091
Main text has 13 pages & 4 figures
openalex publication_date 2020/06/03 · arxiv created 2020/10/09 · arxiv updated 2020/10/12 · openalex created_date 2022/07/26 · openalex updated_date 2026/07/28
For measurements designed to accurately determine layer thickness, there is a natural trade-off between sensitivity to optical thickness and lateral resolution due to the angular ray distribution required for a focused beam. We demonstrate a near-field imaging approach that enables both sub-wavelength lateral resolution and optical thickness sensitivity. We illuminate a sample in a total internal reflection geometry, with a photo-activated spatial modulator in the near-field, which allows optical thickness images to be computationally reconstructed in a few seconds. We demonstrate our approach at 140 GHz (wavelength 2.15 mm), where images are normally severely limited in spatial resolution, and demonstrate mapping of optical thickness variation in inhomogeneous biological tissues.