[1] Xie Kecheng,International Conference on Optoelectronic Scienceand Engineering,ICOESE '90,Beijing China,August 1990,Washington USA:SPIE,1990:443-444
[2] Macleod H A,Appl Opt,1981;20 (1):82-89
[3] Schiller S,Heisig U,Goedicke K.Thin Solid Films,19781 54(1):33
[4] Van Vouros T.Opt Spectra,1977,11:30