Optical isolator

Abstract

Abstract PURPOSE:To obtain an optical isolator having a high quenching characteristic and being free from a polarization dependency by combining four pieces of plate-like double refraction crystals and two pieces of Faraday rotors. CONSTITUTION:At the time of improving the quenching characteristic, it can be attained by increasing the thickness of plate-like double refraction crystals 1-4. Also, since two pieces of Faraday rotors 5, 6 are brought to magnetic saturation in the reverse directions to each other, there is an advantage that they are not influenced against deterioration of the characteristic caused by a temperature variation. Even if the reflected return light is rotated by 45-alpha deg. by the Faraday rotor 6, since a first Faraday rotor 5 is magnetized in the reverse direction, said light turns in reverse by 45+alpha deg. by a first Faraday rotor 5, therefore, since 45 deg. is corrected within a general use temperature range, the quenching characteristic is saved. Also, based on the same theory, even when a light source generates a wavelength displacement by a temperature variation, a stable isolation characteristic is obtained synthetically by allowing the light to pass through the Faraday rotors 5, 6 which are magnetized in the reverse directions to each other. In such a way, the optical isolator being free from a polarization dependency can obtain a quenching characteristic of a stable temperature.

Inventors

• 👤 Yoshihiro Konno
• 👤 良博 今野
• 👤 Nobuo Imaizumi
• 👤 伸夫 今泉

Bibliographic Details