Tunable compound eye cameras

Abstract

We present design and realization concepts for thin compound eye cameras with enhanced optical functionality. The systems are based on facets with individually tunable focus lengths and viewing angles for scanning of the object space. The active lens elements are made of aluminum nitride (AlN)/nanocrystalline diamond (NCD) membranes. This material system allows slow thermally actuated elements with a large deformation range as well as fast piezoelectric elements with a smaller deformation range. Due to the extreme mechanical stability of these materials, we are able to realize microoptical components with optimum surface qualities as well as an excellent long-term stability. We use facets of microlenses with 1 mm in diameter and a tunable focusing power to compensate for the focus shift for different viewing angles during the scanning procedure. The beam deflection for scanning is realized either by laterally shifting spherical elements or by a tunable microprism with reduced aberrations. For both actuators we present a design,fabrication concept and first experimental results

Static and dynamic characterization of AlN and nanocrystalline diamond membranes

“…Recently, several AlN‐NCD heterostructures, made of sputtered AlN on CVD grown NCD films, have been reported for the use in MEMS resonators, surface acoustic wave devices and micro‐optics 12–14. In the development of such structures, the mechanical properties of the thin films play a key role.…”

Simple unimorph deformable mirrors fabricated from piezo buzzers

“…Despite anomalies in the reconstructed defocus aberration (figure 5), we show that the mirror can still be effectively exploited for fast focus control in imaging application, as a contrast to the existing solution using deformable lenses (Pätz et al 2010). To demonstrate this, we built a prototype optical system, where a PointGrey Flea3 FL3-U3-13Y3M-C camera using a Sony IMX035 sensor with a 3.63 μm pixel size was equipped with a C-Mount microscopic lens with 3X optical magnification.…”

Dynamic characterization of thin aluminum nitride microstructures

“…2, the measured resonant frequencies are plotted together with the theoretical curves given by Eq. (2).…”

“…Therefore, they are often not applicable in the fast microelectromechanical systems (MEMSs), as well as in the devices operating in either harsh or biological environments [1]. Using thin film nanodiamond (ND) membranes which shapes are controlled by piezoelectrical AlN actuators [2] will overcome these limits as these materials are known to exhibit exceptional hardness, chemical stability, and high thermal conductivity in addition to optical transparency from ultra-violet to far infrared [3]. In this work, the systematic studies of the basic material and mechanical properties of thin membranes made of AlN as well as of AlN/ND heterostructures are reported.…”