高品质因子氟化镁晶体微腔制备与测试

Based on a linear motor, a high precision scale and a mechanical feedback unit, a precision automatic grinding and polishing system was developed. The system enabled accurately control the size, thickness and shape of the crystal microcavities during preparation. The trapezoidal micro-disk cavity of magnesium fluoride crystal with high quality factor was fabricated by preforming, rough grinding, rough polishing and fine polishing. The surface roughness of magnesium fluoride crystal after precision polishing was characterized to be 2. 84 nm using a white light interferometer. By setting up a taper fiber and crystal microcavity coupling testing system, the quality factor of the prepared crystal microcavity was measured to be 4. 55 × 10 at 1 550 nm by the optical cavity ring-down method.