Deka Nishita, Maker Ashley J, Armani Andrea M
Opt Lett. 2014 Mar 15;39(6):1354-7. doi: 10.1364/OL.39.001354.
Whispering gallery mode microcavities are ideally suited to form microlaser devices because the high circulating intensity within the cavity results in ultralow lasing thresholds. However, to achieve low-threshold Raman lasing in silica devices, it is necessary to have quality factors above 100 million. One approach to circumvent this restriction is to intercalate a sensitizer into the silica, which increases the Raman gain. In the present work, we demonstrate a Raman laser based on a titanium sensitized silica solgel coated toroidal microcavity. By tuning the concentration of the Ti, the Raman efficiency improves over 3× while maintaining sub-mW thresholds.
回音壁模式微腔非常适合用于制造微激光器件，因为腔内的高循环强度会导致超低的激光阈值。然而，要在二氧化硅器件中实现低阈值拉曼激光，品质因数必须高于1亿。一种规避此限制的方法是将敏化剂插入二氧化硅中，这会增加拉曼增益。在本工作中，我们展示了一种基于钛敏化的二氧化硅溶胶凝胶涂覆环形微腔的拉曼激光器。通过调整钛的浓度，拉曼效率提高了3倍以上，同时保持亚毫瓦级的阈值。
