| 摘要 |
An optical multiplexer-demultiplexer consisting essentially of a light-focusing transmission body having a radially graded refractive index distribution and a reflection or transmission type diffraction grating. The transmission body is given an axial length approximately equal to an integral multiple of one quarter of the pitch of undulation of an off-axis input light beam as travelling through the transmission body while the diffraction grating is arranged on the axis of the transmission body at a distance approximately equal to an odd multiple of one quarter of the pitch of beam undulation from one end face of the transmission body which is normal to the axis. A composite light beam directed into the transmission body is dispersed by the diffraction grating into wavelength components, which are separately focused to be extracted as through respective optical fibers. The device needs no separate optical elements such as reflecting mirrors or an independent diffraction grating and is not only particularly compact in size and stable on account of its integral structure but is capable of a high degree of multiplexing.
|
