Microwave seminar | 12 March 2026

The optical theorem is a powerful tool of scattering theory that directly relates the extinction cross section of a scatterer to its forward scattering amplitude. While it is widely used in electromagnetism and optics, its application in acoustics has remained largely unexplored, partly due to experimental limitations. We developed an approach to measure the extinction cross section in a room with pronounced standing waves and applied it in the anechoic chamber of ITMO University to measure the extinction cross section of an acoustic Helmholtz resonator.

Main paper/arXiv, related to the seminar, and other references

[1] Smith, B. V., & Ertugrul, M. G. (1985). A technique for the measurement of extinction cross section. J. Sound Vib., 98(2), 275–288. doi: 10.1016/0022-460X(85)90391-8
[2] Hulst, H. (1981). Dover Books on Physics Light Scattering by Small Particles