Title:
LASER DEVICE AND EXPOSURE METHOD
Document Type and Number:
WIPO Patent Application WO/2001/020397
Kind Code:
A1
Abstract:
A laser device which can be used as a light source for an exposure device, can be downsized, and is easy to maintain. A laser beam (LB6) emitted from a DFB (Distributed feedback) semiconductor laser, for example, and amplified by an optical fiber amplifier is passed through non-linear optical crystals (502, 503, 504) to be sequentially doubled in frequency to thereby generate an ultraviolet-region laser beam (LB5) consisting of an octuple wave. A GdYCOB, that is, Gd¿x?Y¿1-x?Ca¿4?O(BO¿3?)¿3? crystal (0$m(f)x$m(f)1) is used for the non-linear optical crystal (503) for a double wave-to-quadruple wave conversion, and a KAB, that is, K¿2?Al¿2?B¿4?O¿7? crystal for the non-linear optical crystal (504) for a quadruple wave-to-octuple wave conversion. The non-linear optical crystals (502-504) are all fine-tuned in phase match angle by temperature controllers (521-523) respectively.
Inventors:
OHTSUKI TOMOKO (JP)
Application Number:
PCT/JP2000/006131
Publication Date:
March 22, 2001
Filing Date:
September 08, 2000
Export Citation:
Assignee:
NIPPON KOGAKU KK (JP)
OHTSUKI TOMOKO (JP)
OHTSUKI TOMOKO (JP)
International Classes:
G02F1/37; G03F7/20; (IPC1-7): G02F1/37; H01S3/109
Foreign References:
| US5838709A | 1998-11-17 | |||
| EP0919852A1 | 1999-06-02 | |||
| JPH0388379A | 1991-04-12 | |||
| JPH10339891A | 1998-12-22 | |||
| JPH1152443A | 1999-02-26 |
Other References:
V. PETROV ET AL.: "Vacuum ultra violet application of Li2B4O7 crystals: Generation of 100fs pulses down to 170nm", JOURNAL OF APPLIED PHYSICS, vol. 84, no. 11, 1 December 1998 (1998-12-01), pages 5887 - 5892, XP002963518
M. YOSHIMURA ET AL.: "Noncritically phase-matched frequency conversin in CdxY1-xCa4O(BO3)3 crystal", OPTICS LETTERS, vol. 24, no. 4, 15 February 1999 (1999-02-15), pages 193 - 195, XP002935182
ZHANG-GUI HU ET AL.: "A new nonlinear optical borate crystal K2A12B2O7 (KAB)", JAPANESE JOURNAL OF APPLIED PHYSICS, vol. 37, no. 10A, PART 2, 1998, pages L1093 - L1094, XP002935183
SHUJUN ZHANG ET AL.: "Growth and noncritical phase-matching third-harmonic-generation of GdxY1-xCa4O(BO3)3", JOURNAL OF CRYSTAL GROWTH, vol. 213, no. 3/4, 1 June 2000 (2000-06-01), pages 415 - 418, XP002935184
M. YOSHIMURA ET AL.: "Noncritically phase-matched frequency conversin in CdxY1-xCa4O(BO3)3 crystal", OPTICS LETTERS, vol. 24, no. 4, 15 February 1999 (1999-02-15), pages 193 - 195, XP002935182
ZHANG-GUI HU ET AL.: "A new nonlinear optical borate crystal K2A12B2O7 (KAB)", JAPANESE JOURNAL OF APPLIED PHYSICS, vol. 37, no. 10A, PART 2, 1998, pages L1093 - L1094, XP002935183
SHUJUN ZHANG ET AL.: "Growth and noncritical phase-matching third-harmonic-generation of GdxY1-xCa4O(BO3)3", JOURNAL OF CRYSTAL GROWTH, vol. 213, no. 3/4, 1 June 2000 (2000-06-01), pages 415 - 418, XP002935184
Attorney, Agent or Firm:
Omori, Satoshi (Noborito Tama-ku Kawasaki-shi Kanagawa, JP)
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