Patent ID: 6470116
Filing Date: 2002-10-22
Classification: H04B

Abstract:
A bidirectional signal transmission device using light comprising:an optical unit including (1) a first light device facing a second light device, each of the first and the second light devices having a vertical cavity surface emitting laser (VCSEL) unit for emitting light in a direction in which semiconductor material layers are stacked and a photodiode part incorporated with the VCSEL part for receiving incident light, (2) at least one optical fiber installed between the first and the second light devices for transmitting an optical signal, and (3) a first diffraction element installed between the first light device and a first input/output port of the optical fiber, and a second diffraction element installed between the second light device and a second input/output port of the optical fiber, the first and the second diffraction elements for selectively diffracting incident light so that light output from the optical fiber is received by the corresponding photodiode part; a first circuit unit for controlling the first light device so that an electrical signal from a first apparatus is converted into an optical signal, and so that an optical signal transmitted via the optical fiber is converted into an electrical signal and then, transmitted to the first apparatus; and a second circuit unit for controlling the second light device so that an electrical signal from a second apparatus is converted into an optical signal, and so that an optical signal transmitted via the optical fiber is converted into an electrical signal and then transmitted to the second apparatus, wherein signal transmission and reception between the first and the second light devices are performed via a same channel.