Curved focal plane detector array for wide field cameras.

Miniaturization is the main goal for system design in future cameras. This paper offers a novel method to scale down the optical system and to improve the image quality. As with the human retina, the detector array is spherically bent to fit the curved image surface; so the field curvature aberration is directly suppressed, leading to a better resolution and a simplified optical design. By thinning the substrate, the device is monolithically curved without modifying the fabrication process of the active pixels. Optical characterizations have been performed on planar and curved focal plane based cameras to illustrate the optical advantages of detector array curvature.

Compact infrared cryogenic wafer-level camera: design and experimental validation.

We present a compact infrared cryogenic multichannel camera with a wide field of view equal to 120°. By merging the optics with the detector, the concept is compatible with both cryogenic constraints and wafer-level fabrication. The design strategy of such a camera is described, as well as its fabrication and integration process. Its characterization has been carried out in terms of the modulation transfer function and the noise equivalent temperature difference (NETD). The optical system is limited by the diffraction. By cooling the optics, we achieve a very low NETD equal to 15 mK compared with traditional infrared cameras. A postprocessing algorithm that aims at reconstructing a well-sampled image from the set of undersampled raw subimages produced by the camera is proposed and validated on experimental images.

Infrared camera based on a curved retina.

Design of miniature and light cameras requires an optical design breakthrough to achieve good optical performance. Solutions inspired by animals' eyes are the most promising. The curvature of the retina offers several advantages, such as uniform intensity and no field curvature, but this feature is not used. The work presented here is a solution to spherically bend monolithic IR detectors. Compared to state-of-the-art methods, a higher fill factor is obtained and the device fabrication process is not modified. We made an IR eye camera with a single lens and a curved IR bolometer. Images captured are well resolved and have good contrast, and the modulation transfer function shows better quality when comparing with planar systems.

Demonstration of an infrared microcamera inspired by Xenos peckii vision.

We present an original and compact optical system inspired by the unusual eyes of a Strepsipteran insect called Xenos peckii. It is designed for a field of view of 30 degrees and is composed of multiple telescopes. An array of prisms of various angles is placed in front of these telescopes in order to set a different field of view for each channel. This type of camera operates in the [3-5 microm] spectral bandwidth and is entirely integrated in a Dewar in order to maximize its compactness. Experimental images are presented to validate this design.

Compact infrared pinhole fisheye for wide field applications.

The performances of a compact infrared optical system using advanced pinhole optics for wide field applications are given. This concept is adapted from the classical Tisse design in order to fit with infrared issues. Despite a low light gathering efficiency and a low resolution in comparison with classical lenses, pinhole imagery provides a long depth of field and a wide angular field of view. Moreover, by using a simple lens that compresses the field of view, the angular acceptance of this pinhole camera can be drastically widened to a value around 180°. This infrared compact system is named pinhole fisheye since it is based on the field lens of a classical fisheye system.