Bidirectional optical semiconductor apparatus

An optical transmitting/receiving apparatus for bidirectional transmission, comprising:

• means for sending out a first optical signal,
• a first optical waveguiding body for guiding the first optical signal to a transmission path;
• means for receiving a second optical signal,
• a second waveguiding body for guiding said second optical signal from said transmission path;
• a directional coupler in which said first and second optical waveguiding bodies are arranged close to each other so that mode coupling arise, a directional coupling section comprising a part of said directional coupler, approximately half as long as the full coupling length L of said directional coupler for a light having the wavelength of said first optical signal;
• a filter, arranged at the end of said directional coupling section substantially vertically to said first and second optical waveguides, for reflecting at least a part of said first optical signal and transmitting at least a part of said second optical signal;
• and
• means, arranged on the opposite side to said directional coupling section via said filter, for receiving said second optical signal;
• wherein:
• said first and second optical waveguiding bodies are first and second optical waveguides, respectively, formed on the same substrate;
• and
• said directional coupling section consists of said first and second optical waveguides formed close to each other on said substrate.

An optical transmitting/receiving apparatus for bidirectional transmission comprising:

• means for sending out a first optical signal;
• a substrate including a first optical waveguide for entering said first optical signal, a second waveguide for sending out said first optical signal and receiving a second optical signal, and a directional coupling section formed by arranging said first and second optical waveguides close to each other so as to be approximately half as long as the full coupling length L for a light having the wavelength .lambda..sub.1 of said first optical signal;
• and
• a half mirror, arranged at the end of said directional coupling section, for reflecting at least a part of said first optical signal and transmitting at least a part of said second optical signal;
• an optical fiber to be connected to said second optical guide;
• and
• means, arranged on the opposite side to said section formed by arranging said first and second optical waveguides via said half mirror, for receiving said second optical signal.

An optical transmitting/receiving apparatus for bidirectional transmission comprising:

• means for sending out a first optical signal of .lambda..sub.1 in wavelength;
• a substrate including a first optical waveguide for entering said first optical signal, a second waveguide for sending out said first optical signal and receiving a second optical signal of .lambda..sub.2 in wavelength, and a directional coupling section formed by arranging said first and second optical waveguides close to each other so as to be approximately half as long as the full coupling length L for a light having the wavelength .lambda..sub.1 of said first optical signal;
• and
• a filter, arranged at the end of said directional coupling section, for reflecting at least a part of said first optical signal of .lambda..sub.1 in wavelength and transmitting at least a part of said second optical signal of .lambda..sub.2 in wavelength;
• an optical fiber to be connected to said second optical guide;
• and
• means, arranged on the opposite side to said section formed by arranging said first and second optical waveguides via said filter, for receiving said second optical signal.