Controlling the transverse momentum distribution of a light field via azimuth division of a hologram in holographic optical tweezers

Abstract

This study proposes a method for creating a light field with controlled distribution of transverse momentum (TM) by displaying a hologram only in an azimuth region that centers at theta(0) and has a range of Delta theta of a spatial light modulator in holographic optical tweezers. This study utilized ray optics to analyze the TM of the resultant field, revealing that the direction of the TM is determined by the center angle of the azimuth region and that the magnitude of the TM is proportional to sind(Delta theta/2), without regarding the intensity. The relationship was verified experimentally. In addition, this study demonstrated moving particles along a designed path and depleting particles by the fields. (C) 2011 Optical Society of America