Title :
Infrared Scanning Near-Field Optical Microscopy Below the Diffraction Limit
Author :
Sanghera, Jasbinder S. ; Aggarwal, Ishwar D. ; Cricenti, Antonio ; Generosi, Renato ; Luce, Marco ; Perfetti, Paolo ; Margaritondo, Giorgio ; Tolk, Norman H. ; Piston, David
Author_Institution :
Naval Res. Lab., Washington, DC
Abstract :
Infrared scanning near-field optical microscopy (IR-SNOM) is an extremely powerful analytical instrument since it combines IR spectroscopy´s high chemical specificity with SNOM´s high spatial resolution. In order to do this in the infrared, specialty chalcogenide glass fibers were fabricated and their ends tapered to generate SNOM probes. The fiber tips were installed in a modified near-field microscope and both inorganic and biological samples illuminated with the tunable output from a free-electron laser located at Vanderbilt University. Both topographical and IR spectral images were simultaneously recorded with a resolution of ~ 50 and ~ 100 nm, respectively. Unique spectroscopic features were identified in all samples, with spectral images exhibiting resolutions of up to lambda/60, or at least 30 times better than the diffraction limited lens-based microscopes. We believe that IR-SNOM can provide a very powerful insight into some of the most important biomedical research topics.
Keywords :
biomedical equipment; biomedical measurement; biomedical optical imaging; chalcogenide glasses; free electron lasers; glass fibres; image resolution; infrared imaging; infrared spectroscopy; laser applications in medicine; near-field scanning optical microscopy; optical fibre fabrication; IR spectral images; IR spectroscopy; IR-SNOM; SNOM probes; Vanderbilt University; analytical instrument; biological samples; biomedical applications; chalcogenide glass fibers fabrication; chemical specificity; diffraction limitation; infrared scanning near-field optical microscopy; inorganic samples; spatial resolution; topographical images; tunable free-electron laser; Biomedical optical imaging; Chemical analysis; Image resolution; Infrared spectra; Instruments; Optical diffraction; Optical microscopy; Spatial resolution; Spectroscopy; Ultraviolet sources; Infrared fibers; spectroscopy; tapered fiber tips;
Journal_Title :
Selected Topics in Quantum Electronics, IEEE Journal of
DOI :
10.1109/JSTQE.2008.928166