Electro-Optic Nano-Photonic Devices for Detection of Electric Fields from DC to THz Frequency Range

• Main Authors: Rabiei, Payam, Toroghi, Seyfollah
• Format: Conference Proceeding
• Language: English
• Subjects: Electrooptic modulators; Integrated optics; Optical device fabrication; Optical films; Optical polarization; Optical resonators; Optical sensors
• ISSN: 2576-7208
• DOI: 10.1109/ICOPS37625.2020.9717620

Electro-optic (EO) electric-field sensors are dielectric devices that use electro-optic effect to modulate a laser to detect electric fields. These sensors can be used to detect electric fields from DC or near DC frequencies all the way up to THz frequencies. The EO sensors are made from dielectric electro-optic materials and hence do not disturb measurand electric field. Since no electrical wires are used, they are immune to electromagnetic interferences noise and can be used to measure electric field in highly electromagnetically noisy environments such as inside a plasma reactor. Conventional EO sensors use electro-optic crystal to modulate an optical signal and are based on modulation of polarization components in a bulk crystal 1 or modulation of an optical signal in a Mach-Zehnder type optical modulator 2 . In this paper we introduce novel electro-optic e-field sensor based on an electro-optic micro-ring resonator structure or Mach-Zehnder optical modulator structure that are made on thin film lithium niobate crystals. Thin film lithium niobate crystals have significant advantages compared to the conventional methods for electric field sensing. EO sensors based on micro-ring resonators are extremely compact and can achieve a spatial resolution that is 10-20 times lower than conventional electro-optic sensors. In addition, the sensor can achieve much higher sensitivity compared to conventional electro-optic sensors. Thin film lithium niobate Mach-Zehnder sensors allow perfect phase matching and can be used for detection of THz electric fields. In this talk, we will present the principle of operation of the micro-ring and Mach-Zehnder sensors, their structure and the fabrication procedure for the sensor element, the interrogation system architecture and the performance specifications that we have obtained for these sensors for measuring electric fields.