Phase plate technology for laser marking of magnetic discs

Patent · 27 October 1998

OSTI ID:675848

Neuman, B; Honig, J; Hackel, L; Dane, C B; Dixit, S

An advanced design for a phase plate enables the distribution of spots in arbitrarily shaped patterns with very high uniformity and with a continuously or near-continuously varying phase pattern. A continuous phase pattern eliminates large phase jumps typically expected in a grating that provides arbitrary shapes. Large phase jumps increase scattered light outside of the desired pattern, reduce efficiency and can make the grating difficult to manufacture. When manufacturing capabilities preclude producing a fully continuous grating, the present design can be easily adapted to minimize manufacturing errors and maintain high efficiencies. This continuous grating is significantly more efficient than previously described Dammann gratings, offers much more flexibility in generating spot patterns and is easier to manufacture and replicate than a multi-level phase grating. 3 figs.

• Research Organization: University of California
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• Assignee: Univ. of California, Oakland, CA (United States)
• Patent Number(s): US 5,828,491/A/
• Application Number: PAN: 8-777,680
• OSTI ID: 675848
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS
DESIGN
EFFICIENCY
GRATINGS
LASER RADIATION
MAGNETIC DISKS
MASKING