Title :
Nanoscale light-induced phase transformation in alpha-gallium as the source of a broadband optical nonlinearity
Author :
MacDonald, K.F. ; Fedotov, V.A. ; Zheludev, N.I. ; Zhdanov, B.V. ; Knize, R.J.
Author_Institution :
Dept. of Phys. & Astron., Southampton Univ., UK
Abstract :
Summary form only given. Using a tunable optical parametric oscillator we discovered that the interface between gallium and silica displays an exceptionally broadband nonlinearity. At temperatures several degrees below gallium´s melting point (/spl sim/30/spl deg/C) the reflectivity increases by up to 40% in response to 3 ns excitation pulses at wavelengths from 440 to 700 nm. It is shown how the reflectivity change depends on the excitation fluence, and that it saturates at about 6 mJ/cm/sup 2/.
Keywords :
gallium; interface phenomena; laser beam effects; melting; nonlinear optics; 440 to 700 nm; Ga; broadband optical nonlinearity; excitation fluence dependence; gallium/silica interfaces; laser induced thermal melting; light-induced structural change; liquefying gallium; nanoscale light-induced phase transformation; reflective more metallic phase; reflectivity; solid alpha-gallium ground-state phase; temperature distribution dynamics; Fiber nonlinear optics; Frequency; Glass; Laser tuning; Nonlinear optics; Optical fibers; Optical films; Optical saturation; Optical scattering; Optical waveguides;
Conference_Titel :
Lasers and Electro-Optics, 2001. CLEO '01. Technical Digest. Summaries of papers presented at the Conference on
Conference_Location :
Baltimore, MD, USA
Print_ISBN :
1-55752-662-1
DOI :
10.1109/CLEO.2001.947720
