| 摘要 |
<p>Method for fabricating an optical part applicable to the field of optical communication, especially an optical loss filter having a long-period fiber grating for reducing the wavelength dependence of the gain of a rare-earth element doped fiber amplifier and an optical loss filter fabricated by this method. The method for fabricating an optical loss filter in an optical waveguide having a core of specified refractive index comprises a first step of fabricating first and second long-period gratings spaced at a specified interval in the axial direction of the photosensitive core of the optical waveguide and a second step of irradiating the core between the first and second long period gratings with ultraviolet radiation. Since irradiation of the core with ultraviolet radiation can be varied continuously, desired accurate transmission characteristics can be easily imparted to the optical loss filter. Furthermore, a small optical loss filter can be fabricated because the number of long-period gratings to be formed can be decreased.</p> |
