Figure 2

Design of optics.
(A) A ray-trace simulation was used to design the distal optics (L2-L4). (B–D) Spot size with RMS radius of 0.632, 0.794 and 1.94 μm can be achieved at a distance of 0, 75 and 150 μm away from the center of the FOV. The radius of the Airy disk is 0.59 μm.