AbstractWe used the high‐efficiency nonlinear optical effect caused by the photothermal effect of guest‐host (dye‐doped) liquid crystals to form a laser‐induced concave lens by irradiation with a Gaussian beam. The process for forming the laser‐induced concave lens was identified by adapting diffraction theory to the pump‐probe method. We also considered the anisotropy of the thermal conductor in the liquid crystal layer and could explain the laser‐induced concave lens characteristics observed in practice including the dependence on the dye concentration and the effect of the thickness of the liquid crystal layer from the results of three‐dimensional heat conduction analysis. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 87(11): 10–19, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20085