G. A. Neville Connell

Laser-induced local heating of multilayers

For a multilayer structure illuminated by a laser beam, absorption of optical energy in the absorptive layers and the diffusion of the resultant heat throughout the structure are studied. Analytical and numerical procedures for this study are described, and, as a specific example, the profiles of temperature distribution during recording on a magnetooptical disk are presented. The technique is also expected to be of value for studies of thermal marking and laser annealing.

Signal-To-Noise In Magneto-Optic Storage

The power spectral density of the read signal for a magneto-optical readout system based on the polar Kerr effect has been analyzed. A criterion for optimum performance deriving from the signal to noise ratio is then defined and it is shown that a quadrilayer disk structure which acts as an interference device for the enhancement of the Kerr effect is superior to other structures. Results of a thermal calculation for the quadrilayer are then reported. These results clearly indicate that the quadrilayer can be designed to match different levels of laser power available for writing.

Optical properties of amorphous metals using a ratio reflectance method

A method for calculating the optical properties of amorphous metals is described. When the reflectivity at low photon energies is well represented by the Hagen-Rubens equation, the Kramers-Kronig relation can be expressed in terms of a ratio reflectance, and the optical phase so obtained has much greater accuracy than when obtained by the regular approach. As an example, the optical properties of amorphous Fe(80)B(20) are derived.