| 摘要 |
PROBLEM TO BE SOLVED: To provide a small and inexpensive multiplexing and demultiplexing chip, and to provide a small and low-cost optical module for bi-directional transmission using the same. SOLUTION: The multiplexing and demultiplexing chip is provided with a filter film 47 which has a dividing film to branch transmitting light and received light on one of two opposing surfaces and a reflective film 48 on the other opposing surfaces both formed at an arbitrary angle to two opposing surfaces, transmits the transmitting light and received light and reflects third light having a wavelength different from the transmitting light and received light. The optical module which can carry out one-way transmission by the third light at the same time of the bi-directional transmission is attained by changing the incidence optical axis of the transmitting light and the emission optical axis of the received light at the incident side of the transmitting light, and by bringing into line any of the emission optical axis of the transmitting light, the incidence optical axis of the received light and the incidence optical axis or the emission optical axis of the third light at the emission side of the transmitting light. |
