| 摘要 |
PROBLEM TO BE SOLVED: To place an access point which uses a semiconductor optical modulator in operation, without supplying electricity to it. SOLUTION: An optical modulator 15 is used, which uses quantum confinement Stark effect of the multi-quantum well of a semiconductor and is characterized by λS-λPL<60 nm, where λS is the wavelength of light which is superposed on a signal, and λPL is the wavelength corresponding to the energy difference between quantum levels of electrons and positive holes of the multi-quantum well. |
