Akondi Vyas, Kowalski Bartlomiej, Burns Stephen A, Dubra Alfredo
Byers Eye Institute, Stanford University, Palo Alto, California 94303, USA.
Indiana University School of Optometry, Bloomington, Indiana 47405, USA.
Optica. 2020 Nov;7(11):1506-1513. doi: 10.1364/optica.405187. Epub 2020 Oct 27.
High-speed optical systems are revolutionizing biomedical imaging in microscopy, DNA sequencing, and flow cytometry, as well as numerous other applications, including data storage, display technologies, printing, and autonomous vehicles. These systems often achieve the necessary imaging or sensing speed through the use of resonant galvanometric optical scanners. Here, we show that the optical performance of these devices suffers due to the dynamic mirror distortion that arises from the variation in torque with angular displacement. In one of two scanners tested, these distortions result in a variation of signal-to-noise (Strehl) ratio by an order of magnitude across the field of view, degrading transverse resolution by more than a factor of 2. This mirror distortion could be mitigated through the use of stiffer materials, such as beryllium or silicon carbide, at the expense of surface roughness, as these cannot be polished to the same degree of smoothness as common optical glasses. The repeatability of the dynamic distortion indicates that computational and optical corrective methods are also possible.
高速光学系统正在彻底改变生物医学成像领域，包括显微镜检查、DNA测序和流式细胞术，以及许多其他应用，如数据存储、显示技术、印刷和自动驾驶车辆。这些系统通常通过使用共振振镜式光学扫描仪来实现必要的成像或传感速度。在此，我们表明，由于扭矩随角位移变化而产生的动态镜面畸变，这些设备的光学性能会受到影响。在测试的两台扫描仪中的一台中，这些畸变导致整个视场的信噪比（斯特列尔比）变化一个数量级，横向分辨率降低超过2倍。这种镜面畸变可以通过使用更硬的材料（如铍或碳化硅）来减轻，但代价是表面粗糙度增加，因为这些材料无法抛光到与普通光学玻璃相同的光滑度。动态畸变的可重复性表明，计算和光学校正方法也是可行的。
