Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group
  • Applied Spectroscopy
  • Vol. 54,
  • Issue 10,
  • pp. 1515-1520
  • (2000)

Confocal Raman Microscopy: Why the Depth Resolution and Spatial Accuracy Can Be Much Worse than You Think

Not Accessible

Your library or personal account may give you access

Abstract

This paper describes continuing studies on the effect of refraction on the depth resolution and spatial accuracy of confocal Raman microscopy. Previous work showed how the apparent position of interfaces, and their breadth, was grossly in error when "optical sectioning" was carried out with a high-power metallurgical objective (the usual configuration for commercial confocal Raman instruments). Simple equations were presented which model these effects given only the numerical aperture of the objective and sample refractive index. This paper extends these studies to the measurement of the position and thickness of buried structures and shows how the refraction theory provides a good basis for interpreting Raman intensity-depth profiles that have been acquired by optical sectioning of complex structures. To summarize the magnitude of the problem, it is typical for the apparent thickness and positional depth of a buried layer to be about half of the true values—hence, correcting for refraction is critical when interpreting intensity-depth profiles. In order to minimize the effects it is possible to use a specialized objective (e.g., an oil immersion objective) to reduce refraction at the sample surface. Data are presented which show that the apparent position and thickness of structures obtained with such an objective are much closer to the actual values, even when the sample index is not perfectly matched by the coupling fluid. The use of immersion objectives is highly recommended if depth profiling by optical sectioning is to be attempted.

PDF Article
More Like This
Depth profiles in confocal optical microscopy: a simulation approach based on the second Rayleigh-Sommerfeld diffraction integral

Rosario Esposito, Giuseppe Scherillo, Marianna Pannico, Pellegrino Musto, Sergio De Nicola, and Giuseppe Mensitieri
Opt. Express 24(12) 12565-12576 (2016)

Improving spatial resolution of confocal Raman microscopy by super-resolution image restoration

Han Cui, Weiqian Zhao, Yun Wang, Ying Fan, Lirong Qiu, and Ke Zhu
Opt. Express 24(10) 10767-10776 (2016)

High spatial resolution of topographic imaging and Raman mapping by differential correlation-confocal Raman microscopy

Rongji Li, Demin Xu, Angze Li, Yunhao Su, Weiqian Zhao, Lirong Qiu, and Han Cui
Opt. Express 30(23) 41447-41458 (2022)

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Select as filters


Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All Rights Reserved