Temperature dependence of nonlinear optical response in metal/dielectrics composite media

The effective nonlinear optical response in metal/dielectrics composite media is studied as a function of temperature by combining spectral representation with decoupling approximation. Two different microstructures corresponding to those described by Maxwell-Garnett Theory (MGT) and Bruggeman Theory (BT) are examined. The effective nonlinear optical response is dependent on the temperature through the temperature dependence of optical properties of metals. Numerical results show that the effective nonlinear optical properties generally decrease with the increase of temperature and the temperature effect is particularly pronounced at optical frequencies close to surface-plasmon resonance frequencies. Different temperature-dependent nonlinear optical behavior described by MGT and BT shows that the microstructure plays an important role in determining the effective nonlinear response and thus provide a means to examine the possibly realistic models of some composites by measuring their temperature-dependent nonlinear optical response. (C) 1998 Elsevier Science Ltd. All rights reserved.