Akondi Vyas, Castillo Sara, Vohnsen Brian
Advanced Optical Imaging Group, School of Physics, University College Dublin, Dublin 4, Ireland.
Opt Express. 2013 Jul 29;21(15):18261-72. doi: 10.1364/OE.21.018261.
The pyramid wavefront sensor is known for its high sensitivity and dynamic range that can be tuned by mechanically altering its modulation amplitude. Here, a novel modulating digital scheme employing a reflecting phase only spatial light modulator is demonstrated. The use of the modulator allows an easy reconfigurable pyramid with digital control of the apex angle and modulation geometry without the need of any mechanically moving parts. Aberrations introduced by a 140-actuator deformable mirror were simultaneously sensed with the help of a commercial Hartmann-Shack wavefront sensor. The wavefronts reconstructed using the digital pyramid wavefront sensor matched very closely with those sensed by the Hartmann-Shack. It is noted that a tunable modulation is necessary to operate the wavefront sensor in the linear regime and to accurately sense aberrations. Through simulations, it is shown that the wavefront sensor can be extended to astronomical applications as well. This novel digital pyramid wavefront sensor has the potential to become an attractive option in both open and closed loop adaptive optics systems.
金字塔波前传感器以其高灵敏度和动态范围而闻名，该动态范围可通过机械改变其调制幅度来调整。在此，展示了一种采用仅反射相位空间光调制器的新型调制数字方案。调制器的使用允许轻松实现可重构金字塔，通过数字控制顶角和调制几何形状，而无需任何机械移动部件。借助商用哈特曼-夏克波前传感器，同时感测由140个驱动器的变形镜引入的像差。使用数字金字塔波前传感器重建的波前与哈特曼-夏克传感器感测的波前非常紧密地匹配。需要注意的是，可调谐调制对于使波前传感器在线性区域工作并准确感测像差是必要的。通过模拟表明，该波前传感器也可扩展到天文应用。这种新型数字金字塔波前传感器有可能成为开环和闭环自适应光学系统中一个有吸引力的选择。
