A Multiscale, Wide Field, Gigapixel Camera

Abstract

Recent investigations into high pixel count imaging using multiscale optics have led to a novel optical design for a wide field, gigapixel camera. We review the mechanical design and optical performance of this imager. Optical designMultiscale lens design is an attempt at severing the inherent connection between geometric aberrations and aperture size that plagues traditional lenses [1]. By taking advantage of the superior imaging capabilities of small scale optics, a multiscale lens can effectively increase its field of view and image size by simply arraying additional optical elements, similar to a lens array. The resulting partial images can then be stitched post processing to create a single image of a large field.The optical design for the wide field gigapixel imager MC0 (Figure 1) utilizes a multiscale design in conjunction with a monocentric objective lens [2] to achieve near diffraction limited performance throughout the field. A monocentric objective enables the use of identical secondary optics (referred to as micro-optics) greatly simplifying design and manufacturing. Following the multiscale lens design methodology, the FOV is increased by arraying additional micro-optics along the focal surface of the objective. In practice, the FOV is limited by the physical housing. The current design has a FOV of ±60º and is optimized for a pixel pitch of around 2 microns. Figure 1. Optical design of gigapixel imager MC0.

Review of multiscale optical design

“…Prof. David Brady's team at Duke University is developing a number of increasingly higher pixel count cameras, all of them in the multigigapixel class, projected to eventually reach 40-50 Gpixels. The first design, dubbed AWARE 2, uses 2 Gpixels to cover a 120°FOV [55,56]. The resulting curved focal surface, as shown in Fig.…”

“…Single microcamera imaging path with micro-optics and a flat sensor in the back (from[55], courtesy of OSA).…”

Optimization of high-performance monocentric lenses

“…Historically, the more common approach was an achromatic 2GS architecture, used by Sutton in 1856, Baker in 1942 [14], and more recently by Brady and co-workers [1,3] and Ford and co-workers [2,15]. A more complex three-glass symmetric structure (3GS) with third-order aberration analysis was designed and fabricated by Oakley [16] for a panoramic spherical retroreflector.…”

Liquid crystal lens focusing in monocentric multiscale imagers

“…Cossiart and Nayar demonstrated a closely related configuration using a glass ball and single element relay lenses, recording and digitally combining overlapping images from 5 adjacent image sensors 7 . And recently a Gigapixel monocentric multiscale AWARE-2 imager has been demonstrated which integrates a 2-dimensional mosaic of sub-images 8,9 , using the optical layout shown in Figure 1 10 . Figure 1.…”