First order solution generation and optimization of reflective dual-conjugate zoom systems

Adaptive optics (AOs) ophthalmoscopy is a powerful technique for imaging retinas of living subjects at single-cell resolution. Traditional AO ophthalmoscopes use a fixed exit pupil diameter, which is matched to the ocular pupil of a subject. A more efficient ophthalmoscope would allow for a variable exit pupil size to match the variable ocular pupil size of a subject. One method to achieve this is an optical zoom system. To make a zoom system appropriate for use in adaptive optics ophthalmoscopy, it must be simultaneously well corrected for both the field conjugate and the pupil conjugate such that the aberration correction can be successfully applied. The system must also be made of reflective optics to minimize chromatic aberration and spurious back reflections propagating through the system. Both of these factors make for an zoom system that requires tools and methods to be developed to realize successful designs. We present here our work developing a first-order starting point generator, which creates valid first-order solutions that satisfy all the constraints of the system. We then show our techniques for modeling and optimizing the simultaneous conjugates of the system throughout the process of unobscuring the system. We find that to achieve the selected specifications that freeform optics must be used. These surfaces are critical for correcting the residual aberrations introduced in the unobscuring process.