| 摘要 |
An exposure apparatus has a light source comprising a laser device that is small and easy to maintain. The laser device comprises a laser oscillator for generating a single-wavelength laser beam (LB 3 ) within a wavelength range including infrared and visible regions; an optical amplifier ( 18 ) for amplifying a laser beam (LB 3 ); and a wavelength converter for converting the amplified laser beam into ultraviolet light using a nonlinear optical crystal. The optical amplifier ( 18 ) includes a plurality of stages of optical fiber amplifiers ( 22, 25 ) for sequential amplification of the laser beam (LB 3 ), and a narrow-band filter ( 24 A) and an isolator (IS 3 ) arranged between optical fiber amplifiers. |
