Phase contrast imaging is performed for live biological species using photothermal induced birefringence in dye doped liquid crystals. Using typical 4-f configuration, when liquid crystal cell is at back focal plane of Fourier lens, low spatial frequencies at center of Fourier spectrum are intense enough to induce local liquid crystal molecules into isotropic phase, whereas high spatial frequencies on the edges are not intense enough and remain in anisotropic phase. This results in π/2 phase difference between high and low spatial frequencies. This simple, inexpensive, all-optical, user-friendly, self-adaptive phase contrast imaging technique using low-power laser offers several distinct advantages.
Yelleswarapu, Chandra S.; Kothapalli, Sri-Rajasekhar; Aranda, Francisco J.; Rao, D.V.G.L.N.; Vaillancourt, Yvonne; and Kimball, Brian R., "Phase contrast imaging using photothermally induced phase transitions in liquid crystals" (2006). Physics Faculty Publications. 1.
American Institute of Physics
Copyright 2006 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.