Optical sorting and detection of sub-micron objects in a motional   standing wave
  An extended interference pattern close to surface may result in both a transmissive or evanescent surface fields for large area manipulation of trapped particles. The affinity of differing particle sizes to a moving standing wave light pattern allows us to hold and deliver them in a bi-directional manner and importantly demonstrate experimentally particle sorting in the sub-micron region. This is performed without the need of fluid flow (static sorting). Theoretical calculations experimentally confirm that certain sizes of colloidal particles thermally hop more easily between neighboring traps. A new generic method is also presented for particle position detection in an extended periodic light pattern and applied to characterization of optical traps and particle behavior 
Tomas Cizmar (1), Martin Siler (1), Mojmir Sery (1), Pavel Zemanek (1)   Veneranda Garces-Chavez (2), Kishan Dholakia (2) ((...