Fiberoptic apparatus for measuring electromagnetic field intensity with an electro-optic sensor
First Claim
1. An electromagnetic field intensity measuring apparatus comprising:
- measuring light generating means for emitting a coherent measuring light linearly polarized in a given direction;
optical fiber means for conducting said measuring light to an electromagnetic field measuring place;
sensor means located in said electromagnetic field measuring place for receiving the measuring light from said optical fiber means, said sensor means being adapted to modulate the amplitude of the measuring light entering the sensor means depending on the intensity of the electromagnetic field, the modulated light being then re-applied to said optical fiber means;
polarization rotating means located between said measuring light generating means and said optical fiber means, said polarization rotation means being operative to cause the polarized wavefront of the, measuring light passed therethrough to rotate a given angle relative to the direction of passage;
a polarization beam splitter disposed between said measuring light generating means and said polarization rotating means, said polarization beam splitter being operative to permit only the measuring light from said measuring light generating means to pass through said polarization beam splitter and also to reflect the modulated measuring light inputted through said polarization rotating means in a predetermined direction; and
calculator means for calculating the intensity of electromagnetic field in the electromagnetic field measuring place, based on the amplitude of the measuring light reflected by said polarization beam splitter,said sensor means comprising;
antenna section for detecting the electromagnetic field and also for outputting a voltage corresponding to the intensity of the detected electromagnetic field;
an integrated optics, said integrated optics being separate from said optical fiber means, said integrated optics including a waveguide formed therein, one end of said waveguide being a measuring light entering section and the other end thereof being a measuring light reflecting section, andoptical amplitude modulator means operative to apply a voltage signal outputted from said antenna section to said waveguide and also to modulate the amplitude of the measuring light Propagated through the waveguide depending on the intensity of the electromagnetic field before the modulated measuring light is outputted therefrom.
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Accused Products
Abstract
An electromagnetic field intensity measuring apparatus comprises a sensor located in the electromagnetic field measuring place for receiving the measuring light from the optical fiber, the sensor being adapted to modulate the measuring light entering the sensor depending on the intensity of the electromagnetic field, the modulated light being then re-applied to the optical fiber; a polarization rotating device located between the measuring light generating device and the optical fiber, the polarization rotation device being operative to cause the polarized wavefront of the measuring light passed therethrough to rotate a given angle in the direction of passage; and a polarization beam splitter disposed between the measuring light generating device and the polarization rotating device, the polarization beam splitter being operative to permit only the measuring light from said measuring light generating device to pass through said polarization beam splitter and also to reflect the modulated measuring light inputted through the polarization rotating device in a predetermined direction. The electromagnetic field intensity in the measuring place can be calculated, based on the amplitude of the measuring light reflected by the polarization beam splitter.
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Citations
20 Claims
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1. An electromagnetic field intensity measuring apparatus comprising:
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measuring light generating means for emitting a coherent measuring light linearly polarized in a given direction; optical fiber means for conducting said measuring light to an electromagnetic field measuring place; sensor means located in said electromagnetic field measuring place for receiving the measuring light from said optical fiber means, said sensor means being adapted to modulate the amplitude of the measuring light entering the sensor means depending on the intensity of the electromagnetic field, the modulated light being then re-applied to said optical fiber means; polarization rotating means located between said measuring light generating means and said optical fiber means, said polarization rotation means being operative to cause the polarized wavefront of the, measuring light passed therethrough to rotate a given angle relative to the direction of passage; a polarization beam splitter disposed between said measuring light generating means and said polarization rotating means, said polarization beam splitter being operative to permit only the measuring light from said measuring light generating means to pass through said polarization beam splitter and also to reflect the modulated measuring light inputted through said polarization rotating means in a predetermined direction; and calculator means for calculating the intensity of electromagnetic field in the electromagnetic field measuring place, based on the amplitude of the measuring light reflected by said polarization beam splitter, said sensor means comprising; antenna section for detecting the electromagnetic field and also for outputting a voltage corresponding to the intensity of the detected electromagnetic field; an integrated optics, said integrated optics being separate from said optical fiber means, said integrated optics including a waveguide formed therein, one end of said waveguide being a measuring light entering section and the other end thereof being a measuring light reflecting section, and optical amplitude modulator means operative to apply a voltage signal outputted from said antenna section to said waveguide and also to modulate the amplitude of the measuring light Propagated through the waveguide depending on the intensity of the electromagnetic field before the modulated measuring light is outputted therefrom. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 14, 15, 16, 18, 19, 20)
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11. An electromagnetic field intensity measuring apparatus comprising:
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measuring light generating means for emitting a coherent measuring light lineraly polarized in a given direction; optical fiber means for conducting said measuring light to an electromagnetic field measuring place; sensor means located in said electromagnetic field measuring place for receiving the measuring light from said optical fiber means, said sensor means being adapted to modulate the amplitude of the measuring light entering the sensor means depending on the intensity of the electromagnetic field, the modulated light being then re-applied to said optical fiber means; polarization rotating means located between said measuring light generating means and said optical fiber means, said polarization rotation means being operative to cause the polarized wavefront of the measuring light passed therethrough to rotate a given angle relative to the direction of passage; a polarization beam splitter disposed between said measuring light generating means and said polarization rotating means, said polarization beam splitter being operative to permit only the measuring light from said measuring light generating means to pass through said polarization beam splitter and also to reflect the modulated measuring light inputted through said polarization rotating means in a predetermined direction; calculator means for calculating the intensity of electromagnetic field in the electromagnetic field measuring place, based on the amplitude of the measuring light reflected by said polarization beam splitter; said sensor means comprising an antenna section for detecting the electromagnetic field and also for outputting a voltage corresponding to the intensity of the detected electromagnetic field, an integrated optics including a waveguide formed therein, one end of said waveguide being a measuring light entering section and the outer end thereof being a measuring light reflecting section, and optical amplitude modulator means operative to apply a voltage signal outputted from said antenna section to said waveguide and also to modulate the amplitude of the measuring light propagated through the waveguide depending on the intensity of the electromanetic field before the modulated measuring light is outputted therefrom; and wherein said calculator means comprises an optical detector for converting the inputted measuring light into an electric signal, a first signal processing section for extracting and outputting a signal component used to detect the electromagnetic field intensity from said electric signal, a second signal processing section for extracting and outputting a low-frequency component signal containing any disturbance component from said electric signal, and a calculating section for removing any disturbances component from the electromagnetic field intensity detection signal outputted from said first signal processing section and for calculating the electromagnetic field intensity in the electromagnetic field measuring place, based on the signal outputted from said second signal processing section, whereby the electromagnetic field intensity can be measured without affection of said disturbance. - View Dependent Claims (12, 13)
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17. An electromagnetic field intensity measuring apparatus comprising:
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measuring light generating means for emitting a coherent measuring light linearly polarized in a given direction; optical fiber means for conducting said measuring light to an electromagnetic field measuring place; sensor means located in said electromagnetic field measuring place for receiving the measuring light from said optical fiber means, said sensor means being adapted to modulate the amplitude of the measuring light entering the sensor means depending on the intensity of the electromagnetic field, the modulated light being then re-applied to said optical fiber means; polarization rotating means located between said measuring light generating means and said optical fiber means, said polarization rotation means being operative to cause the polarized wavefront of the measuring light passed therethrough to rotate a given angle relative to the direction of passage; a polarization beam splitter disposed between said measuring light generating means and said polarization rotating means, said polarization beam splitter being operative to permit only the measuring light from said measuring light generating means to pass through said polarization beam splitter and also to reflect the modulated measuring light inputted through said polarization rotating means in a predetermined direction; calculator means for calculating the intensity of electromagnetic field in the electromagnetic field measuring place, based on the amplitude of the measuring light reflected by said polarization beam splitter; wherein said sensor means comprises an antenna section for detecting the electromagnetic field and also for outputting a voltage corresponding to the intensity of the detected electromagnetic field, an integrated optics including a waveguide formed therein, one end of said waveguide being a measuring light entering section and the outer end thereof being a measuring light reflecting section, and optical amplitude modulator means operative to apply a voltage signal outputted from said antenna section to said waveguide and also to modulate the amplitude of the measuring light propagated through the waveguide depending on the intensity of the electromagnetic field before the modulated measuring light is outputted therefrom; wherein said waveguide includes first and second modulating waveguide portions branched at a branching and combining point, the other end of each of said first and second modulating waveguide portions including said measuring light reflecting portion formed therein, said optical amplitude modulation means including electrode means formed therein such that the voltage signal from said antenna section will be applied to said first and second modulating waveguide portions as voltage signals having the opposite polarities to each other, the measuring light parts propagating through the respective modulating waveguide portions being changed in phase before they are re-combined and caused to interfere with each other at said branching and combining point, whereby the measuring light having its amplitude modulated depending on the electromagnetic field intensity can be outputted from said optical amplitude modulator means; and a polarizer located between said polarization rotating means and said optical fiber means, said polarizer being operative to permit only the measuring light having its polarized wavefront rotated by the polarization rotating means through the given angle to pass therethrough, whereby the measuring light inputted from said integrated optics through said optical fiber means to said polarizer can be outputted to said polarization rotating means after any noise component has been removed.
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Specification