Development of an optical cavity with residual strain free for optical frequency standards

2014 Fiscal Year Final Research Report

• Project/Area Number: 25630167
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Measurement engineering
• Research Institution: Tohoku University
• Principal Investigator: KUSHIBIKI Jun-ichi 東北大学, 工学(系)研究科(研究院), 名誉教授 (50108578)
• Co-Investigator(Kenkyū-buntansha): ARAKAWA Mototaka 東北大学, 大学院医工学研究科, 特任助教 (00333865) ; OHASHI Yuji 東北大学, 金属材料研究所, 助教 (50396462)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: 光キャビティー / 超低膨張材料 / 超精密超音波計測 / 加工プロセス / 熱処理プロセス / 残留歪み

Outline of Final Research Achievements

Ultra-highly-stabilized and ultra-high-finesse optical cavities have been developed to realize ultra-narrow-linewidth lasers for optical frequency standards. TiO2-SiO2 glass is mainly used for the material of cavities. The fabrication process of cavity spacers includes machining processes such as drilling, grinding and lapping. Relaxation of the residual strain introduced by the machining gives rise to long-term length changes of cavities, resulting in long-term frequency changes, viz., creep. It is an important development issue to be resolved for obtaining an ultrastable optical cavity. In this study, we investigated the fabrication process conditions and the heat-treatment conditions to minimize the residual strain, and developed a proper procedure of fabricating a cavity spacer.

Free Research Field

工学