| 摘要 |
PURPOSE:To perform optical demultiplexing and multiplexing by a small transmission loss, by constituting such stages as selectively absorb or reflect specified wavelength, of plural dielectric substrates having a wavelength selecting film on one surface, and providing these stages in a state that they have been inclined by an incident angle. CONSTITUTION:Incident light IL consisting of wavelength lambda1-lambdan is made incident to a transmistting and reflecting filter partIof the first stage, which consists of substrates 4-1, 4-1' provided with reflecting films 3-1, 3-1' for transmitting only light of the wavelength lambda1 and reflecting the light of other wavelength, on the inside surface, and has been provided by inclining it by an incident angle theta, and the transmitted light of the wavelength lambda1 reflects only the light of the wavelength lambda1 in the same way, it is reflected repeatedly in a filter II of an inclined angle theta, and thereafter, is outputted. On the other hand, as for the remaining lights lambda2-lambdan, only the light of wavelength of lambda2 is transmitted by a filter part III placed so as to be inclined by theta from the filter partI of the first, stage, and the remaining part is made incident to the next stage. Said process is repeated, and the light of lambda3-lambdan is multiplexed and outputted in order. |
