Anomalous gradient force on colloidal particles suspended in an optically anisotropic liquid crystal

Igor Poberaj; Miha Skarabot; Dusan Babic; Igor Musevic

doi:10.1117/12.559563

18 October 2004 Anomalous gradient force on colloidal particles suspended in an optically anisotropic liquid crystal

Igor Poberaj, Miha Skarabot, Dusan Babic, Igor Musevic

Proceedings Volume 5514, Optical Trapping and Optical Micromanipulation; (2004) https://doi.org/10.1117/12.559563
Event: Optical Science and Technology, the SPIE 49th Annual Meeting, 2004, Denver, Colorado, United States

Abstract

We report on an observation of attractive gradient force on dielectric particles suspended in a medium with a higher refractive index. This unexpected phenomenon was observed with micron sized silica spheres (n=1.37) suspended in optically anisotropic nematic liquid crystal (n_o=1.5 and n_e=1.7). The newly discovered interaction has a range an order of magnituded bigger than the laser beam waist diameter. Above transition temperature, where nematic order of a liquid crystal is lost, the gradient force becomes repulsive and it's range is reduced to expected values. We attribute an anomalous gradient force in nematic phase to two phenomena: particle dressing with a liquid crystal molecules resulting in a colloid with a higher effective index of refraction than surroundings and laser field induced distortino of nematically ordered liquid crystal molecules.

Citation Download Citation

Igor Poberaj, Miha Skarabot, Dusan Babic, and Igor Musevic "Anomalous gradient force on colloidal particles suspended in an optically anisotropic liquid crystal", Proc. SPIE 5514, Optical Trapping and Optical Micromanipulation, (18 October 2004); https://doi.org/10.1117/12.559563

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available