Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group

Measurement of the size and refractive index of a small particle using the complex forward-scattered electromagnetic field

Not Accessible

Your library or personal account may give you access

Abstract

We have previously shown that interferometry may be used to detect the phase shift of a focused beam caused by a small particle [ Appl. Phys. Lett. 55, 215 ( 1989)]. This is a useful method for detecting small particles in liquids and with the ability to distinguish bubbles from particles. In that measurement, however, only the phase shift, given by the real part of the forward-scattered field, was detected. By measurement of both the real and imaginary parts of the forward-scattered field, additional information is obtained so that the refractive index and size of a nominally spherical particle may be determined. This measurement is analogous to ellipsometric measurements of thin films, where knowledge of both a phase and amplitude quantity allows one to determine a thin-film refractive index and thickness. Using an optical system based on Nomarski optics, we have shown that it is possible to distinguish four classes of particulate material in liquids within the noise constraints of our system. Thus low dielectrics (e.g., SiO2), moderate dielectrics (e.g., Si3N4), bubbles, and metals–absorbers (e.g., Al, C) can be differentiated as well as sized more accurately.

© 1991 Optical Society of America

Full Article  |  PDF Article
More Like This
Refractive-index measurements for the correction of particle sizing methods

Norbert Roth, Klaus Anders, and Arnold Frohn
Appl. Opt. 30(33) 4960-4965 (1991)

Two optical methods for simultaneous measurement of particle size, velocity, and refractive index

Amir Naqwi, Franz Durst, and Xiaozhi Liu
Appl. Opt. 30(33) 4949-4959 (1991)

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

Figures (10)

You do not have subscription access to this journal. Figure files 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

Equations (9)

You do not have subscription access to this journal. Equations 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