A Measurement of LSF of PSTM Imaging With the Image of Step Spread

Review of near-field optical microscopy

“…PSTM has 1 2 orders better than A-SONM in resolution, contrast and transmitting effect. The best experimental result of PSTM we got is the value of the full-width at halfmaximum 2.8 nm [53], and the routine resolution of PSTM is 10 20 nm. The resolution of PSTM is decided by the size of the center of the bare fiber tip, and the resolution of the A-SNOM is approximately given by the size of the metal aperture wall.…”

Comparison of PSTM with A-SNOM

“…We have got the FWHM of Line-Spread-Function (LSF) about 3nm in our PSTM experiment [11,121 In both of A-SNOM and PSTM the detecting light are all penetrating the sample and picking the information of sample, but the action mechanism in A-SNOM is more complex than that in PSTM. In commercial A-SNOM only the "allow light" is used for imaging and the "forbidden light" is abandoned [13] j which The "forbidden light" is more pure evanescent wave but lost.…”