OPTICAL ISOLATOR.

摘要

An optical isolator comprising a polarizer, an analyzer, a Faraday rotor and a permanent magnet for magnetizing the Faraday rotor and inducing a Faraday effect. Degradation of isolation characteristics occurs near a critical temperature (0 DEG C or 70 DEG C) of a practical temperature range of from about 0 to 70 DEG C if adjustment and assembly are made in such a manner that maximum isolation is accomplished at the ambient temperature and for the wavelength used for the assembly. Therefore, the temperature position of maximum isolation is controlled by assembling the isolator at room temperature and for a wavelength which is shifted by a very small wavelength DELTA lambda from the wavelength lambda used so that maximum isolation can be obtained at an arbitrary use temperature by utilizing temperature dependence of the Faraday rotor.