| 摘要 |
PROBLEM TO BE SOLVED: To provide a Faraday rotator which can be used for a light source in a comparatively shorter wavelength region than a near-infrared wavelength region by making the thickness of a paramagnetic garnet single crystal containing Tb hardly having an optical absorption as a host rare-earth element thinner up to a level where the paramagnetic garnet single crystal can be used for the Faraday rotator, while suppressing the optical absorption, and to provide an optical isolator. SOLUTION: The Faraday rotator for short-wavelength light is configured including the paramagnetic garnet single crystal and a bismuth-substituted rare earth iron garnet single crystal. The paramagnetic garnet single crystal contains Tb as the host rare-earth element and has a light transmittance of over 99% with respect to light in a wavelength region of 1,030 nm to 1,090 nm. The Faraday rotation directions of the paramagnetic garnet single crystal and the bismuth-substituted rare-earth iron garnet single crystal are set to be the same and a magnetic field in which the total of the rotation angles of the paramagnetic garnet single crystal and the bismuth-substituted rare-earth iron garnet single crystal is 45°is applied. Further, the wavelengthλof the light entering the Faraday rotator is set to be 1,030 nm to 1,090 nm. COPYRIGHT: (C)2008,JPO&INPIT
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