Magneto-optic media and system optimization

摘要

Magneto-optic media and system optimization including a set of optimized magneto-optic media for use in a magneto-optic recording and readout system employing an incident readout light beam of a given fixed power, Po. The beam is delivered in a linearly polarized state to the magneto-optic media and the magneto-optic radiation received from the media is detectable by the system. Each member of the set of media comprises a reflective layer having a predetermined thickness, a first transparent layer overlying the reflecting layer and having a predetermined thickness and refractive index and a second light transmissive layer having a predetermined thickness and exhibiting absorptivity at the wavelength of said incident readout light beam and having magneto-optic conversivity and perpendicular anisotropy. Members of the set of optimized magneto-optic media may further included a third transparent layer overlaying the second transmissive layer and having a predetermined thickness and refractive index. The combination of these layers exhibit antireflectivity and the incident light absorbed in the media is captured in the second light transmissive layer and the predetermined layer thicknesses and refractive index are chosen to maximize signal to noise ratio (SNR) according to the relationship <IMAGE> where rx represents the reflected component of the linearly polarized incident beam ry represents the reflected magneto-optically induced component in an orthogonal direction, ai is the ith element of the set }ai}0 that represents variable parameters of the chosen readout system, N is the number of elements in the set {ai} and f is a function which is determined by the chosen readout system.