1. US5689391 - Magneto-optic multitrack reading head having a plurality of reflective rays

A magneto-optic multitrack reading head on which incident light impinges. The magneto-optic head includes a first layer of magnetic material exhibiting a Kerr effect and which partially reflects the incident light to generate a first reflection ray and which partially transmits the incident light to generate an internal ray. The magneto-optic head further includes a second layer of magnetic material and a layer of non-magnetic material, the non-magnetic layer having a thickness of one-half of a wavelength of the incident light and formed between the first and second layers of magnetic material and through which the internal ray passes. The internal ray is further reflected after passing through the layer of non-magnetic material to generate a second reflection ray parallel to and in-phase with the first reflection ray. The above structure improves the merit factor and signal-to-noise ratio of the magneto-optic reading head.