Patent ID: 11881900
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Telecommunications (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 9:
10. A spatial light frequency transmission method comprising:
emitting guide light from a guide light source;
forming a first double phase conjugate mirror in a photorefractive crystal by scattering of reference signal light and the guide light, the reference signal light having a first frequency different from a second frequency of the guide light and being incident on the photorefractive crystal via space after being transmitted from a transceiver on another side, the guide light being incident on the photorefractive crystal in a reverse direction to a direction of the reference signal light;
coupling the reference signal light being phase-conjugate light of the guide light by the first double phase conjugate mirror emitted from the photorefractive crystal, to an optical fiber;
causing return signal light, to be incident on the photorefractive crystal, obtained by shifting a third frequency of the reference signal light that is the phase-conjugate light of the guide light by the first double phase conjugate mirror, after reflection to be different from the first frequency of the reference signal light and the second frequency of the guide light; and
forming a second double phase conjugate mirror in the photorefractive crystal by scattering of the return signal light and the reference signal light incident on the photorefractive crystal, and emitting the return signal light to the transceiver on the other side from the photorefractive crystal as phase-conjugate light of the reference signal light by the second double phase conjugate mirror.