With the development of photonic communication, all optics devices are necessary. The realization of all optics devices depends largely on the preparation of suitable materials. Within the materials, Glasses with high nonlinear optical susceptibilities have a lot of advantages and become unreplacable photonic materials. This paper reports nonlinear optical phenomena in glass, method of measurement, nonlinear optical glass materials and method of preparation. Heavy metal oxide glasses(HMO glasses) which are characteristics of high figure of merit because of high nonlinear refractive index and short response time are predicted to be a focus of studies.