Abstract

We present an angular-scattering optical method that is capable of measuring the mean size of scatterers in static ensembles within a field of view less than 20 μm in diameter. Using interferometry, the method overcomes the inability of intensity-based models to tolerate the large speckle grains associated with such small illumination areas. By first estimating each scatterer’s location, the method can model between-scatterer interference as well as traditional single-particle Mie scattering. Direct angular-domain measurements provide finer angular resolution than digitally transformed image-plane recordings. This increases sensitivity to size-dependent scattering features, enabling more robust size estimates. The sensitivity of these angular-scattering measurements to various sizes of polystyrene beads is demonstrated. Interferometry also allows recovery of the full complex scattered field, including a size-dependent phase profile in the angular-scattering pattern.

© 2013 Optical Society of America

Measurement of angular distributions by use of low-coherence interferometry for light-scattering spectroscopy

Adam Wax, Changhuei Yang, Ramachandra R. Dasari, and Michael S. Feld
Opt. Lett. 26(6) 322-324 (2001)

Integrated Raman- and angular-scattering microscopy

Zachary J. Smith and Andrew J. Berger
Opt. Lett. 33(7) 714-716 (2008)

Fourier-domain angle-resolved low coherence interferometry through an endoscopic fiber bundle for light-scattering spectroscopy

John W. Pyhtila, Jeffrey D. Boyer, Kevin J. Chalut, and Adam Wax
Opt. Lett. 31(6) 772-774 (2006)

Fourier transform light scattering angular spectroscopy using digital inline holography

Kyoohyun Kim and YongKeun Park
Opt. Lett. 37(19) 4161-4163 (2012)

Fourier-domain low-coherence interferometry for light-scattering spectroscopy

Adam Wax, Changhuei Yang, and Joseph A. Izatt
Opt. Lett. 28(14) 1230-1232 (2003)