Optical attenuator
AssigneeFujitsu Limited
InventorNobuhiro Fukushima
Life of this patent
Estimating the term…
Abstract
A specific polarized light component out of a light wave passed through a magneto-optic crystal (for example YIG) is extracted by a polarizer. The intensity of the light beam output from the polarizer depends on strength and direction of magnetic fields applied to the magneto-optic crystal. The magneto-optic crystal is applied with a first and a second magnetic field acting in directions different from each other and the strength of the composite magnetic field of them is set to exceed a predetermined value at all times. By varying at least one of the first and second magnetic fields, the attenuation factor in the magneto-optic crystal can be changed continuously and with good reproducibility.
Claims50
An apparatus comprising:
- an optical amplifier amplifying a light;
- and
- an optical attenuator variably attenuating the amplified light without mechanically moving along an optical path of the amplified light, wherein the apparatus is a repeater.
An apparatus comprising:
- an optical amplifier amplifying a light;
- and
- an optical attenuator including a polarizing part and a polarization rotating part which operate together to variably attenuate the amplified light, wherein the apparatus is a repeater.
A method comprising:
- optically amplifying a light by a repeater;
- and
- variably attenuating the amplified light by the repeater without mechanically moving along an optical path of the amplified light.
A method comprising:
- optically amplifying a light by a repeater;
- polarizing the amplified light by the repeater;
- and
- rotating the polarization of the amplified light by the repeater, said polarizing and said rotating operating together to variably attenuate the amplified light by the repeater.
An optical communication system comprising:
- a transmitter transmitting a light;
- a repeater including
- an amplifier optically amplifying the transmitted light, and
- an optical attenuator variably attenuating the amplified light without mechanically moving along an optical path of the amplified light, and outputting the attenuated light;
- and
- a receiver receiving the attenuated light.
A method comprising:
- transmitting a light;
- optically amplifying the transmitted light by a repeater;
- variably attenuating the amplified light by the repeater without mechanically moving along an optical path of the amplified light;
- and
- receiving the attenuated light.
An apparatus comprising:
- an optical amplifier amplifying a light;
- and
- an optical attenuator variably attenuating the amplified light at an output of the optical amplifier without mechanically moving along an optical path of the amplified light.
An apparatus comprising:
- an optical amplifier amplifying a light;
- and
- an optical attenuator including a polarizing part and a polarization rotating part which operate together to variably attenuate the amplified light at an output of the optical amplifier.
A method comprising:
- optically amplifying a light with an optical amplifier;
- and
- variably attenuating the amplified light at an output of the optical amplifier without mechanically moving along an optical path of the amplified light.
A method comprising:
- optically amplifying a light with an optical amplifier;
- polarizing the amplified light;
- and
- rotating the polarization of the amplified light, said polarizing and said rotating operating together to variably attenuate the amplified light at an output of the optical amplifier.
An optical communication system comprising:
- a transmitter transmitting a light;
- an amplifier optically amplifying the transmitted light;
- an optical attenuator variably attenuating the amplified light at an output of the amplifier without mechanically moving along an optical path of the amplified light, and outputting the attenuated light;
- and
- a receiver receiving the attenuated light.
A method comprising:
- transmitting a light;
- optically amplifying the transmitted light with an optical amplifier;
- and
- variably attenuating the amplified light at an output of the optical amplifier without mechanically moving along an optical path of the amplified light.
Dependencies are inferred from the claim text.