Non-destructive procedure for viewing formats on tape

Tape inspection would be simplified considerably by the use of a nondestructive process. In that way magneto-optical garnets must be considered as a significant improvement for reading the recorded tracks and checking compliance with the format. Magneto-optical readout heads allow both high data rate transfer and static imaging and are developed to play video and audio tapes and magnetic discs. Magnetic domains are energized by the leakage flux from the bit transition record on the medium. Vertical domains are optically detected using the Faraday rotation on the magnetic garnets. Growth processes by liquid phase epitaxy, and magnetic properties of thin film garnets are discussed. Some experimental results are commented on