The intensity of a beam of light used to etch concentric servo tracks (12) on a magnetic medium is adjusted with an acousto-optical device to maintain the energy density delivered by the beam substantially constant while the optics (71) which generate the beam move radially of the disk (61).

Title
Acousto-optical intensity control of laser beam
Application Number
PCT/US1993/005407
Publication Number
1993/025341
Application Date
June 8, 1993
Publication Date
December 23, 1993
Inventor
Wilson Scott
Bero James
Wallentine Don W
Thomas Fred Charles
Agent
KURTZ Richard E
Assignee
Minnesota Mining And Manufacturing Company
IPC
G11B 05/82
G11B 05/596
B23K 26/08
B23K 26/06
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