Development of a gravity meter using an optical spring effet inside Fabry-Perot cavity

2016 Fiscal Year Final Research Report

• Project/Area Number: 25610131
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Solid earth and planetary physics
• Research Institution: The University of Tokyo
• Principal Investigator: Miyoki Shinji 東京大学, 宇宙線研究所, 准教授 (20302680)
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: Ｆａｂｒｙ－Ｐｅｒｏｔ共振器 / Optical Spring / 精密長さ計測 / 半共振 / 光輻射圧

Outline of Final Research Achievements

We developed a novel technique for a gravity meter using optical radiation pressure to obtain better sensitivity than that of a superconductive gravity meter. In this scheme, an optical Fabry-Perot(FP) cavity is set vertically and is set semi-resonant state to obtain an optical spring effect. Additionally, one of mirrors for the FP cavity is planed to be levitated by radiation pressure of a laser beam inside the Fabry-Perot cavity by setting the weight of the mirror light. Although we encountered an unstable phenomena due to the optical spring state, we succeeded to keep the semi-resonant state by a moderate feedback control system and verified the effect of the radiation pressure inside the FP cavity.

Free Research Field

精密長さ計測