| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive and compact communicating optical device to be easily manufactured. SOLUTION: The optical device 56 includes an optical block 57. A common terminal 16b for receiving divergent light of long wavelength for bi-directional communication and outputting light of short wavelength and an input terminal 16a for receiving divergent light of short wavelength from a light source 15a are formed on one end of the block 57. An output terminal 16c for sending light of long wavelength to a photodetector 15b is formed on the other end. The block 57 is also provided with a wavelength selection filter 54 for permitting the transmission of long-wavelength light from a common terminal to the photodetector and selectively reflecting short-wavelength light from an input terminal to the common terminal and 1st and 2nd CGH elements 51, 52 for guiding and converging the divergent light from the input terminal to the common terminal through the filter 54. The 2nd CGH element has a converging function for converging the divergent light of long wavelength from the common terminal. |
