Electric field vector detection method and electric field vector detection device
원문보기
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
G01J-005/02
G01J-001/44
G01J-004/04
G01J-001/42
G01J-001/04
G01J-003/433
G01J-003/42
G01J-003/02
G01R-015/24
G01R-029/08
G01N-021/3581
출원번호
US-0950617
(2015-11-24)
등록번호
US-9612153
(2017-04-04)
우선권정보
JP-2014-238686 (2014-11-26)
발명자
/ 주소
Kawada, Yoichi
Yasuda, Takashi
Takahashi, Hironori
출원인 / 주소
HAMAMATSU PHOTONICS K.K.
대리인 / 주소
Drinker Biddle & Reath LLP
인용정보
피인용 횟수 :
2인용 특허 :
2
초록▼
In this electric field vector detection method, an electro-optic crystal, where a (111) surface of an optical isotropic medium is cut out, is used as a terahertz wave detection element. The method includes: causing polarization of probe light of ultrashort pulsed light to be circular polarization; a
In this electric field vector detection method, an electro-optic crystal, where a (111) surface of an optical isotropic medium is cut out, is used as a terahertz wave detection element. The method includes: causing polarization of probe light of ultrashort pulsed light to be circular polarization; allowing the probe light having circular polarization to enter the terahertz wave detection element and probing the terahertz wave; modulating the probe light, having probed the terahertz wave, by a rotating analyzer and detecting the modulated probe light by a photodetector; performing lock-in detection of a detection signal from the photodetector by a lock-in detector using a frequency based on a rotational frequency of the rotating analyzer as a reference signal; and detecting an electric field vector of the terahertz wave based on a detection signal from the lock-in detector.
대표청구항▼
1. An electric field vector detection method for detecting an electric field vector of a terahertz wave, wherein ultrashort pulsed light is used as probe light and an electro-optic crystal, where a (111) surface of an optical isotropic medium is cut out, is used as a terahertz wave detection element
1. An electric field vector detection method for detecting an electric field vector of a terahertz wave, wherein ultrashort pulsed light is used as probe light and an electro-optic crystal, where a (111) surface of an optical isotropic medium is cut out, is used as a terahertz wave detection element for detecting the terahertz wave, the method comprising:causing polarization of the probe light to be circular polarization;allowing the probe light having circular polarization to enter the terahertz wave detection element and probing the terahertz wave;modulating the probe light, having probed the terahertz wave, by a rotating analyzer and detecting the modulated probe light by a photodetector;performing lock-in detection of a detection signal from the photodetector by a lock-in detector using a frequency based on a rotational frequency of the rotating analyzer as a reference signal; anddetecting an electric field vector of the terahertz wave based on a detection signal from the lock-in detector. 2. The electric field vector detection method according to claim 1, wherein amplitude of an electric field vector of the terahertz wave is detected based on amplitude of the detection signal from the lock-in detector, and, a direction of an electric field vector of the terahertz wave is detected based on a phase of the detection signal from the lock-in detector. 3. The electric field vector detection method according to claim 1, wherein a dual phase lock-in detector is used as the lock-in detector. 4. The electric field vector detection method according to claim 1, wherein a terahertz wave generating element configured to generate the terahertz wave by incidence of pump light is used,the method further comprising:branching the ultrashort pulsed light into the probe light and the pump light; andmodulating, in a cyclic manner, the pump light incident on the terahertz wave generating element by an optical modulator. 5. The electric field vector detection method according to claim 4, wherein, when a rotational frequency of the rotating analyzer is defined as f1 and a modulation frequency of the pump light is defined as f2, lock-in detection is performed while a frequency of the reference signal in the lock-in detector is defined as f2±2f1. 6. An electric field vector detection device for detecting an electric field vector of a terahertz wave, the device comprising: a polarization adjusting unit configured to cause polarization of probe light of ultrashort pulsed light to be circular polarization;a terahertz wave detection element including an electro-optic crystal, where a (111) surface of an optical isotropic medium is cut out;a rotating analyzer configured to modulate the probe light having probed the terahertz wave;a photodetector configured to detect the probe light having been modulated by the rotating analyzer;a lock-in detector configured to perform lock-in detection of a detection signal from the photodetector using a frequency based on a rotational frequency of the rotating analyzer as a reference signal; andan electric field vector detection unit configured to detect an electric field vector of the terahertz wave based on a detection signal from the lock-in detector. 7. The electric field vector detection device according to claim 6, wherein the electric field vector detection unit detects amplitude of an electric field, vector of the terahertz wave based on amplitude of the detection signal from the lock-in detector and a direction of an electric field vector of the terahertz wave based on a phase of the detection signal from the lock-in detector. 8. The electric field vector detection device according to claim 6, wherein the lock-in detector is a dual phase lock-in detector. 9. The electric field vector detection device according to claims 6, further comprising: a terahertz wave generating element configured to generate the terahertz wave by incidence of pump light;a branching unit configured to branch the ultrashort pulsed light into the probe light and the pump light; andan optical modulator configured to modulate the pump light in a cyclic manner. 10. The electric field vector detection device according to claim 9, wherein, when a rotational frequency of the rotating analyzer is defined as f1 and a modulation frequency of the pump light is defined as f2, the lock-in detector performs lock-in detection while defining a frequency of the reference signal as f2±2f1.
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이 특허에 인용된 특허 (2)
Popa-Simil, Liviu, Multi-band terahertz receiver and imaging device.
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