| 摘要 |
PURPOSE:To easily modulate large output laser beams also by compensating natural double refraction generated by plural electro-optic crystals arranged so that respective optical axes are inclined 90 deg. each other around an optical axes by using natural double refraction generated by another electro-optic crystal, and simultaneously modulating optical beams with different wavelengths. CONSTITUTION:An electro-optical crystal made of the same material as that of an electro-optical crystal 12 and having the same shape and same size is arranged between the crystal 12 and an analyzer 13. The electro-optic crystal 15 is arranged so that its optical axis direction (e) is the Y direction [i.e. in clined from the optical axis direction (e) of the crystal 12 by 90 deg. around an optical axis Z] and its electrode 11 is connected to the electrode 11 of the crystal 12 in parallel. Thereby, natural double refraction generated by the crystal 12 is compensated by the natural double refraction of the crystal 15 and an optical beam modulator for excellently extincting projection light beams when an impressed voltage V is zero volt independently of the wavelength of a laser beam 2. |
