| 摘要 |
PURPOSE: To obtain a thin-film waveguide polarizing rotator which attains substantially zero net linear double refraction by using the rotor in such a manner that the various factors of linear double refraction are offset by each other. CONSTITUTION: The thin film 30 of the polarizing rotor 10 is so produced that the one or plural linear double refraction components of the code reverse from the code of the shape linear double refraction associated with this film 30 are received in a film magnetization direction 40 adopted in the operation of the rotor 10 at the point of the wavelength of the incident electromagnetic radiation on the rotor 10. The film 30 is first formed relatively thick and the scale of the shape linear double refraction is made smaller than the scale of the linear double refraction of the opposite code. The initial thickness of the film 30 is then continuously decreased while the scale of the net linear double refraction is kept monitored until the various contributions to the net linear double refraction intrinsically offset each other by using, for example, a conventional etching technique. As a result, the polarizing rotor which attains the substantially zero net linear double refraction, i.e., the value equal to or below about 0.05 of the value ofαexpressed by equation I without applying a stress thereon from outside.
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