| 摘要 |
PURPOSE:To eliminate the band limitation owing the wavelength dispersion of optical fibers by reverse-coupling the light from the incident side optical guide to the exit side optical guide by way of the grating of changing periods disposed between the 1st and the 2nd cores. CONSTITUTION:The optical guide of dielectric or semiconductor is formed by a clad region 1, core region 2 and clad region 3, and a clad region 3, core region 4 and clad region 5 form an optical guide in a similar manner. Here, if the light of different wavelengths, say, lambda1, lambda2, lambda3... enters the right side through the guides 1-2-3 from the left side of the figure, the light of the wavelength lambda1 is coupled to the guides 3-4-5 by the grating 6 and propagates to the left side but the light of the other wavelengths lambda2, lambda3... does not cause coupling and passes therethrough. In the grating 7, only the light of the wavelength lambda2 couples and in the grating 8, only the light of the wavelength lambda3 causes coupling. Thereafter, the light is coupled to the guides 3-4-5 at the points differing with every wavelength in the similar manner. |
