Abstract
The extinction cross section for an arbitrary spherical particle that is embedded in an absorbing medium is derived by considering that which is measured in an actual extinction experiment. The resultant “optical theorem” is similar in form to the optical theorem for particles in a nonabsorbing medium. Calculations of extinction by germanium particles that are embedded in a polyethylene medium at room temperature have been performed for far-infrared frequencies (50–200 cm −1). If the imaginary part of the medium refractive index is ignored, then particulate extinction is underestimated by factors of between 2 and 4 over the frequency range of interest for 0.02-μm-radius spheres. In addition, there is a significant shift of a bulk germanium absorption maximum, which is not predicted when the medium is assumed to be nonabsorbing. For larger particles, the relative error decreases but still may be significant.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.