Patent ID: 7551537
Filing Date: 2009-06-23
Classification: B82Y,G11B

Abstract:
1. An optical recording medium master disc exposure apparatus comprising: an exposure light source which generates an ultrashort wave pulse laser light with a resonator arrangement having a resonator path with a resonator length; a modulating means for modulating intensity of light from said exposure light source in response to recording information; and a focusing optical system for focusing light modulated by said modulating means on a photoresist on an optical recording medium master disc to thereby pattern-expose said photoresist in response to said recording information, wherein, said ultrashort wave pulse laser light has a repetitive frequency which is synchronized to be an integral multiple in a range from one time to 20 times as high as the clock frequency of said recording information, and said optical recording medium master disc exposure apparatus includes a synchronizing mechanism for varying the resonator length of said ultrashort wave pulse laser to mode-lock the repetitive frequency of said ultrashort wave pulse laser light in synchronism with said clock frequency to thereby cause said ultrashort wave pulse laser to emit light pulses at said repetitive frequency, said synchronizing mechanism operative to compare said clock frequency with a frequency of said ultrashort wave pulse laser light and to vary said resonator length.