Focal length measurement of microlens-array based on wavefront testing principle of Hartmann-Shack sensor

Microlens array wavefront measurement based on transport of intensity equation and hybrid Gerchberg and Saxton iteration

“…The greatest feature of microlens is that they are small in size, light in weight, and easy to integrate. It not only plays an important role in the military field, but also is widely used in various industrial cameras and detector [1]~ [3] . However, various types of industrial devices using microlens arrays have strict requirements for Microlens light field imaging, and the wavefront consistency problem of microlens arrays will greatly affect the performance of the device.…”

“…At present, there are three major types of methods for wavefront measurement of microlens: direct measurement with a wavefront sensor, interferometric measurement and non-interferometric measurement. The most commonly used wavefront sensor today is the Shack-Hartmann wavefront sensor [3] , where the position of the point focused by each microlens can be matched to a certain area of the wavefront. However, for a high-pixel CCD or CMOS, the pixel utilization of the microlens is only a few tenths of that of the CCD pixels, resulting in a low image resolution.…”