公开(公告)号：SG68651A1

公开(公告)日：1999-11-16

申请号：SG1998000466

申请日：1998-03-02

Applicant: IBM

Inventor： BAUMGART PETER MICHAEL ,  BRANNON JAMES HAMMOND ,  BOON CHIE CHING ,  POUR IRAJ KAKESH ,  TAM ANDREW CHING

IPC: G02F1/11 ,  G02F1/33 ,  G11B5/84 ,  G11B7/085 ,  G11B7/135

Abstract: A laser system concurrently directs highly equivalent diffracted beams (14a,14b) derived from an initial laser beam (16) to both sides of a substrate. The diffracted beams are generated with sufficient energy to soften spots on the surfaces of a substrate (95) to form texture bumps as are used on substrates for magnetic disks. The diffracted beams are generated by a multichannel acousto-optic modulator (MCAOM) having at least two channels. The crystal (12) in the MCAOM has at least two mounting faces oriented so that the acoustic transducers (13a,13b) mounted thereon generate acoustic fields which intersect the incident laser beam at a common angle. i.e.. the Bragg angle. Energising any of the transducers causes a corresponding first order beam to be diffracted out. Preferably the diffracted beams are generated by alternating driving signals to transducers to produce two beams with pulse intensity greater than 50% of that of the incident beam which can be directed to opposite sides of the substrate (95) for extremely uniform texturing.