超精密加工の技術を用いて，切削加工のみで高Q値微小光共振器を作製した．高Q値を得るために従来は，研磨加工が必要だったが，超精密加工による延性加工モードを実現すれば，滑らかな表面を得ることができる．延性モード加工条件を明らかにして，切削加工のみでMgF2微小光共振器を作製し，Q値1億を達成した．形状を所望の形に設計することができる．2次分散と4次分散を設計した微小光共振器を用いて，光パラメトリック発振実験を行った．励起光から遠く離れた波長で位相整合が取れるために，1オクターブ以上周波数が離れた間隔でシグナル光とアイドラー光を発生させることができた．
We fabricated a high-Q microcavity only by cutting by using the ultraprecision machining. To date, post-polishing was needed to obtain a high Q microcavity, but we demonstrated that a smooth surface is obtained if a ductile mode cutting is applied that is realized by ultra-precision processing. The ductile mode cutting conditions were studied, and the MgF2 micro-optical resonator was fabricated only by cutting, where we achieved a Q value of 100 million. The shape of the cavity is obtained as designed. Optical parametric oscillation experiments were carried out by using micro-optical resonators of which second-order dispersion and fourth-order dispersion are designed accurately. Since the phase matching can be achieved at a wavelength far from the pump light, the signal and the idler light could be generated at frequencies interval of larger than one octave.

研究種目 : 挑戦的研究 (萌芽)
研究期間 : 2018～2019
課題番号 : 18K19036
研究分野 : 光エレクトロニクス