Open AccessTemperature sensitivity of scattering-type near-field nanoscopic imaging in the visible range
Author(s) -
Amun Jarzembski,
Cedric Shaskey,
Ryan A. Murdick,
Keunhan Park
Publication year - 2019
Publication title -
applied optics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.668
H-Index - 197
eISSN - 2155-3165
pISSN - 1559-128X
DOI - 10.1364/ao.58.001978
Subject(s) - near field scanning optical microscope , optics , materials science , microscopy , optical microscope , scattering , image resolution , interferometry , signal (programming language) , near and far field , scanning electron microscope , physics , computer science , programming language
Due to its superb imaging spatial resolution and spectroscopic viability, scattering-type scanning near-field optical microscopy (s-SNOM) has proven to be widely applicable for nanoscale surface imaging and characterization. However, limited works have investigated the sensitivity of the s-SNOM signal to sample temperature. This paper reports the sample temperature effect on the non-interferometric (self-homodyne) s-SNOM scheme at a visible wavelength (λ=638 nm). Our s-SNOM measurements for an arrayed vanadium/quartz sample demonstrate a monotonic decrease in signal intensity as sample temperature increases. As a result, s-SNOM imaging cannot distinguish quartz or vanadium when the sample is heated to ∼309 K: all signals are close to the root-mean-square noise of the detection scheme used for this study (i.e., 19 μV-rms). While further studies are required to better understand the underlying physics of such temperature dependence, the obtained results suggest that s-SNOM measurements should be carefully conducted to meet a constant sample temperature condition, particularly when a visible-spectrum laser is to be used as the light source.