US 11,892,479 B2
Interference type optical magnetic field sensor device
Mitsunori Miyamoto, Nagano (JP); Toshiya Kubo, Nagano (JP); Toshiroh Sato, Nagano (JP); and Makoto Sonehara, Nagano (JP)
Assigned to CITIZEN FINEDEVICE CO., LTD., Yamanashi (JP); CITIZEN WATCH CO., LTD., Tokyo (JP); and SHINSHU UNIVERSITY, Nagano (JP)
Appl. No. 17/627,118
Filed by CITIZEN FINEDEVICE CO., LTD., Yamanashi (JP); CITIZEN WATCH CO., LTD., Tokyo (JP); and Shinshu University, Nagano (JP)
PCT Filed Mar. 31, 2020, PCT No. PCT/JP2020/014925
§ 371(c)(1), (2) Date Jan. 13, 2022,
PCT Pub. No. WO2021/019839, PCT Pub. Date Feb. 4, 2021.
Claims priority of application No. 2019-141404 (JP), filed on Jul. 31, 2019.
Prior Publication US 2022/0268818 A1, Aug. 25, 2022
Int. Cl. G01R 15/24 (2006.01); G01R 33/032 (2006.01)
CPC G01R 15/246 (2013.01) [G01R 33/0322 (2013.01)] 5 Claims
OG exemplary drawing
 
1. An interference type optical magnetic field sensor device, comprising:
a light emitter configured to emit a first linearly polarized light;
a first optical element configured to emit a first linearly polarized wave and a second linearly polarized wave in response to the first linearly polarized light incident on the first optical element, and emit a second linearly polarized light in response to a third linearly polarized wave and a fourth linearly polarized wave incident on the first optical element;
at least one pair of light transmissive magnetic field sensor elements to be disposed within a magnetic field across the measured conductor, configured to change the phase of transmitted light in accordance with the magnetic field, and fixing a relative position therebetween;
an optical path including a first optical path configured to propagate the first linearly polarized wave and the fourth linearly polarized wave, and a second optical path configured to propagate the second linearly polarized wave and the third linearly polarized wave, wherein the optical path is connected to the first optical element and the magnetic field sensor elements;
a detected signal generator configured to output a detected signal corresponding to the magnetic field, by receiving two components of the second linearly polarized light, and convert to the electrical signal; and
an optical branching element configured to transmit the first linearly polarized light to the first optical element and branch the second linearly polarized light to the detected signal generator, wherein
when the first linearly polarized wave is incident on one of the magnetic field sensor elements, the one emits first return light, and when second return light is incident on one of the magnetic field sensor elements, the one emits the fourth linearly polarized wave, and
when the first return light is incident on the other of the magnetic field sensor elements, the other emits the third straight line polarized wave, and when the second linearly polarized wave is incident on the magnetic field sensor element, the other emits the second return light.