| 摘要 |
PURPOSE:To secure low insertion loss and a high amplification factor for light having specific wavelength by specifying the angle of Faraday rotation of a Faraday rotator. CONSTITUTION:This is a polarized light independent type optical isolator which is equipped with a polarized light separating plate and the Faraday rotator 4 and excites semiconductor laser light of l.55mum in wavelength into light of 1.48mum in wavelength, and the angle of Faraday rotation of the Faraday rotator for the light of 1.55mum in wavelength is 43-45 deg.. Namely, the optical isolator is manufacture by using rutile double refraction flat plates 3A-3C which have 600, 420, and 420mum (ratio 2<1/2>:1:1) of separation into, for example, ordinary and extraordinary light beams and the Bi-substituted magnetic garnet Faraday rotator 4 having the 43-45 deg.-angle of Faraday rotation for the light beams of 1.55 and 1.48mum in wavelength. Consequently, the optical isolator which has the low insertion loss for the light beams of both 1.55 and 1.48mum in wavelength is obtained. |
