Opt Express. 2023 May 8;31(10):15495-15513. doi: 10.1364/OE.488516.
It is known that the quality factors (Q) of photonic crystal nanocavities vary from sample to sample due to air-hole fabrication fluctuations. In other words, for the mass production of a cavity with a given design, we need to consider that the Q can vary significantly. So far, we have studied the sample-to-sample variation in Q for symmetric nanocavity designs, that is, nanocavity designs where the positions of the holes maintain mirror symmetry with respect to both symmetry axes of the nanocavity. Here we investigate the variation of Q for a nanocavity design in which the air-hole pattern has no mirror symmetry (a so-called asymmetric cavity design). First, an asymmetric cavity design with a Q of about 250,000 was developed by machine learning using neural networks, and then we fabricated fifty cavities with the same design. We also fabricated fifty symmetric cavities with a design Q of about 250,000 for comparison. The variation of the measured Q values of the asymmetric cavities was 39% smaller than that of the symmetric cavities. This result is consistent with simulations in which the air-hole positions and radii are randomly varied. Asymmetric nanocavity designs may be useful for mass production since the variation in Q is suppressed.
众所周知，由于空气孔制造波动，光子晶体纳米腔的品质因数（Q）会在不同样品之间发生变化。换句话说，对于具有给定设计的腔的批量生产，我们需要考虑到 Q 值可能会有很大的变化。到目前为止，我们已经研究了对称纳米腔设计的 Q 值的样品间变化，也就是说，孔的位置相对于纳米腔的两个对称轴保持镜像对称的纳米腔设计。在这里，我们研究了空气孔图案没有镜像对称（所谓的非对称腔设计）的纳米腔设计的 Q 值变化。首先，通过使用神经网络的机器学习开发了具有约 25 万 Q 值的非对称腔设计，然后我们用相同的设计制造了五十个腔。我们还制造了五十个具有约 25 万 Q 值的对称腔作为比较。测量的非对称腔的 Q 值变化比对称腔小 39%。这一结果与空气孔位置和半径随机变化的模拟结果一致。非对称纳米腔设计可能对批量生产有用，因为 Q 值的变化得到了抑制。
