| 摘要 |
PURPOSE:To achieve the miniaturization and higher performance by forming N pieces of directional couplers in a medium of transmitting light and N-1 pieces of Y-type optical branching circuits. CONSTITUTION:N pieces (N>=2) of directional couplers C1thru CN are formed in a medium composed of a semiconductor or dielectric which transmits light and these are subsequently coupled by N-1 pieces of Y-type optical branching circuits Y1 thru YN-1. And the coupling length li(i = 1 to N) is made li = gim (T1/Ti) l1 [gim is the constant determined by the values of N and i, Ti is the branching characteristic parameters of the (i)th directional coupler, l1 is the coupling length of the 1st directional coupler]. Then, at the time when the light incident to port 1 is branched and emits from ports 2, 3, the channel splitting wavelength width becomes less than several 10 Angstrom . In addition, light loss becomes slight and light integration is made easier. |
