磁光薄膜表面反射二次谐波Kerr效应的理论研究

Theoretical Study of Kerr Effect of Second-Harmonic That It's Surface Reflection of Magnetic-Optic Film

利用级数展开法,推出了磁光薄膜各晶面对p极化光反射的二次谐波强度和磁光Kerr角;分析了入射角与各晶面反射的二次谐波强度及磁光Kerr角的相互关系,结果发现:①各晶面反射的二次谐波强度与入射光的强度之比正比于入射光的强度,且是入射角的函数,同时其比值在入射角的取值范围内存在极值;②各晶面反射的二次谐波的Kerr角与入射光的强度无关,只与薄膜的性质和入射角有关;③从保护薄膜的角度来看,读写激光不宜采用正入射方式.

Having given the strength magnetic-optic Kerr angle of second-harmonic about it is reflection of crystal surface each of magnetic-optic film to p polarization light by spread method of series Having Analysed the mutual relation of incidence angle with strength and magnetic-optic Kerr angle of second-harmonic of each crystal surface to reflect, a result discovered： ①The ratio of strength about crystal surface to reflect each second-harmonic and incident light is direct ratio, and it is the function of angle of incidence, the ratio has extremum at taking value scope of incidence angle; ②Kerr angle of reflection second-harmonic each surface is unconcerned, it is concerned with incidence angle and the nature of thin film. ③From point of view of protective thin film, Laser beams of reading and writing do not suit to adopt straight incident way.