Guided-wave optical multi/demultiplexer
AssigneeHitachi Cable, Ltd.
InventorsHideaki Arai, Hisato Uetsuka
Life of this patent
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Abstract
A guided-wave optical multi/demultiplexer is capable of providing a wide wavelength band freely. Each of two directional couplers is constructed so that the coupling ratio of light intensity in the wavelength .lambda..sub.2 is at least 50% and the coupling ratio of light intensity in the wavelength .lambda..sub.3 having a wavelength band in close proximity to the wavelength .lambda..sub.1 is 0% or 100%, the light in the wave band containing the wavelength .lambda..sub.1 and the wavelength .lambda..sub.3 and the light in the wave band containing the wavelength .lambda..sub.2 being multiplexed and demultiplexed.
Claims10
A guided-wave optical multi/demultiplexer having directional couplers in both sides of a phase shift region having a difference of optical path length which differs from an integral times a value multiplying an inverse number of an equivalent refractive index to a wavelength .lambda..sub.1 by one-half times the value and agrees with an integral times a value multiplying an inverse number of an equivalent refractive index to a wavelength .lambda..sub.2, and is constructed so that the coupling ratio of light intensity at said wavelength .lambda..sub.2 is at least 50%, the light in the wave band containing said wavelength .lambda..sub.1 and the light in the wave band containing said wavelength .lambda..sub.2 being multiplexed and demultiplexed, wherein:
- each of said two directional couplers is constructed so that the coupling ratio of light intensity in said wavelength .lambda..sub.2 is at least 50% and the coupling ratio of light intensity in said wavelength .lambda..sub.3 having a wavelength band in close proximity to said wavelength .lambda..sub.1 is 0% or 100%, the light in the wave band containing said wavelength .lambda..sub.1 and said wavelength .lambda..sub.3 and the light in the wave band containing said wavelength .lambda..sub.2 being multiplexed and demultiplexed.
A method of multiplexing and demultiplexing light in a wave band containing a wavelength .lambda..sub.1 and light in a wave band containing a wavelength .lambda..sub.2 using a guided-wave optical multi-demultiplexer in which two guided-wave paths are provided on a substrate, said two guided-wave paths being placed in proximity to each other with a given gap therebetween and in parallel to each other along a given length in two positions to form two directional couplers, at least one of said guided-wave paths being by-passed between said two positions to form a directional coupler, wherein:
- said two directional couplers are constructed so that the coupling ratio of light intensity at said wavelength .lambda..sub.2 is 50% and the coupling ratio of light intensity at said wavelength .lambda..sub.3 having a wavelength band in close proximity to said wavelength .lambda..sub.1 is 0% or 100% the light in the wave band of 1.3 .mu.m containing said wavelength .lambda..sub.1 and said wavelength .lambda..sub.3 and the light in the wave band of 1.55 .mu.m containing said wavelength .lambda..sub.2 being multiplexed and demultiplexed.
Dependencies are inferred from the claim text.