Application of the Simulated Annealing Algorithm to Film Optical Constant Inversion
Kong Ying-xiu · Journal of Xi'an Technological University · 2011
The difference between the actual and theoretical optical constants has an effect on monitoring.On basis of the transmittance spectral curve the difference has been measured.A simulated annealing algorithm is applied to the inversion of optical constants n,k and d of layers deposited.Using the simulated annealing algorithm,the finding range of a new value is controlled adaptively according to the acceptance rate for finding the better new solution when the dropping temperature is t.After the new value is determined,the temperature decreases by the way of exponential drop,whose temperature rate varies with acceptance probability P;When the termination condition is satisfied after the temperature drops continuously,the algorithm stops.After the algorithm has been improved,it is applied to the example that membrane ZnS is deposited on the substrate of quartz glass.The values of n,k and d are obtained in a shorter time and the optimization speed and the algorithm efficiency are increased.