**4.2. PoC prototype**

essential to minimize chromatic errors, in particular longitudinal chromatic aberration

The illuminated field on the retina (approximately 10×10 degrees) is limited by a square field stop in a retinal conjugate plane. Visible light from the eye is reflected by a cold mirror (CM) and relayed through a pair of matched photographic lenses, chosen to minimize noncommon path errors. An adjustable iris between the two photographic lenses is used to set

Imaging is performed with a science grade monochromatic CCD science camera with 2048×2048 pixels and a square pixel cell size of 7.4 µm is used for imaging. The size of the

(FWHM) of the Airy disk in the image plane at 575 nm is 15 µm and hence the image is sam‐

**Figure 4.** Basic layout of the PoC prototype. Abbreviations: BPF – band-pass filter, BS – beamsplitter, CLA – collimating lens array, CM – cold mirror, DM1 – pupil DM, DM2 – field DM, FS –field stop, FT – flash tube, LA – lenslet array, M – mirror, P – pupil conjugate plane, PBS – pellicle beamsplitter, PFP/PFA – polarization filters, PL – photographic lens, PMF – flash pupil mask, PMGS – GS pupil mask, R – retinal conjugate plane, SF – spatial filter, SM – spherical mirror, SLD –

superluminescent diode, TL – trial lens. Fixed corrective lenses are either lens pairs or single lenses.

. The full width at half maximum

the pupil size used for imaging, corresponding to a diameter of 6 mm at the eye.

pled according to the Nyquist-Shannon sampling theorem (two pixels per FWHM).

(LCA) [38] in the image plane of the retinal camera.

10 Adaptive Optics Progress

CCD chip corresponds to a retinal FOV of 6.7×6.7 deg2

A PoC prototype (Fig. 4) has been developed to evaluate the clinical relevance of DCAO wide-field high-resolution retinal imaging. The prototype is currently under construction and features several improvements with regards to the DCAO demonstrator. Most signifi‐ cant among those are that the order in which DM corrections are imposed has been changed and a novel implementation of GS creation (patent pending). The size of the PoC prototype has been greatly reduced compared with the optical table design of the DCAO demonstrator to a compact joystick operated tabletop instrument 600×170×680 mm (H×W×D) in size. The opto-mechanical layout comprises five modules: a GS generation module, a main module, a WFS module, a flash module, and an imaging module.
