Fremgangsmåde til at producere en Faraday-rotator

摘要

A Faraday rotator is provided that includes a Faraday element having a Verdet constant at a wavelength of 1.06 µm of at least 0.27 min/(Oe·cm), a first hollow magnet disposed on the outer periphery of the Faraday element, and second and third hollow magnet units disposed so as to sandwich the first hollow magnet on the optical axis. The second and third hollow magnet units include 2 or more magnets equally divided in a direction of 90 degrees relative to the optical axis. A magnetic flux density B (Oe) applied to the Faraday element is in the range of 0.5 × 10 4 ‰¤ B ‰¤ 1.5 × 10 4 . The Faraday element has a length L (cm) in the range of 0.70 ‰¤ L ‰¤ 1.10, and an external diameter D (cm) in the range of 0.20 ‰¤ D ‰¤ 0.60 and consists of terbium oxide (Tb 2 O 5 ) and one element selected from the group of scandium, yttrium, and lanthanoid elements other than terbium.