| US 7,590,312 B2 | ||
| Interferometer optical switch and variable optical attenuator | ||
| Takayuki Mizuno, Yamato (Japan); Hiroshi Takahashi, Atsugi (Japan); Tsutomu Kitoh, Atsugi (Japan); Manabu Oguma, Yamato (Japan); and Shunichi Souma, Atsugi (Japan) | ||
| Assigned to Nippon Telegraph and Telephone Corporation, Tokyo (Japan) | ||
| Appl. No. 10/536,649 PCT Filed Jul. 02, 2004, PCT No. PCT/JP2004/009773 § 371(c)(1), (2), (4) Date May 27, 2005, PCT Pub. No. WO2005/003852, PCT Pub. Date Jan. 13, 2005. |
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| Claims priority of application No. 2003-191797 (JP), filed on Jul. 04, 2003. | ||
| Prior Publication US 2006/0072866 A1, Apr. 06, 2006 | ||
| Int. Cl. G02F 1/01 (2006.01); G02F 1/035 (2006.01); G02B 6/26 (2006.01); G02B 6/42 (2006.01) | ||
| U.S. Cl. 385—1 [385/2; 385/3; 385/15; 385/16; 385/20; 385/42; 385/140] | 98 Claims |
| 1. An interferometer optical switch comprising an optical waveguide circuit including:
a first optical multi/demultiplexing device;
an optical delay line including two optical waveguides connected to said first optical multi/demultiplexing device;
a second optical multi/demultiplexing device connected to said optical delay line;
one or more input waveguides connected to said first optical multi/demultiplexing device;
one or more output waveguides connected to said second optical multi/demultiplexing device; and
a phase shifter installed in said optical delay line, and wherein
at least one of said first optical multi/demultiplexing device and said second optical multi/demultiplexing device is a phase
generating coupler which produces a wavelength-dependent phase difference;
characterized in that assuming that λ is the wavelength, 2πφ1(λ) is the phase produced by the first optical multi/demultiplexing device, 2πφΔL(λ) is the phase difference of the optical delay line with an optical path length difference of ΔL, and 2πφ2(λ) is the phase produced by the second optical multi/demultiplexing device, the sum of the phase difference 2π{φ1(λ) +φΔL(λ)+φ2(λ)} is set at a constant value regardless of wavelength.
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