Comparison of a kaleidoscope-based multi-view infrared system with its TOMBO-based counterpart

Abstract

Multi imaging snapshot systems are used for a wide range of applications in all the spectral ranges. We propose here a study and a realization of a multi-view snapshot system using a kaleidoscope in the Long-Wave Infrared (LWIR) and compatible with uncooled infrared detectors such as microbolometers. The optical system has a high numerical aperture, a wide range of fields of view and uses a single focal plane array. We will establish here the advantages of this technology on other design strategies and especially the kaleidoscope design will be compared with the TOMBO design. Then the optical conception rules for every subset of the kaleidoscope architecture will be described and the results of a first demonstrator will be presented. The features of this system will be compared with a TOMBO-based system with a front afocal.

Three multispectral configurations of a snapshot kaleidoscope-based camera in long wavelength infrared spectral band

“…The spectral overlap creates a lot of unused areas on the FPA for our experimental camera, and we lost one advantage of this system over other multispectral solutions [26]. We can conclude that the distance between the focal plane and the filters is critical in the case of a high opened system, typically f /1.…”

“…Since unconventional lenses have to be made and aligned, this solution becomes difficult to apply for more than nine images. Finally, multichannel architectures must manage the cross talk between the different channels, usually by using walls, since a field stop is not easily implemented for a high numerical aperture [22].…”

“…In a previous article [25], we showed that an LWIR kaleidoscope-based multiview system can be designed. In terms of size, this system is equivalent to a lenslet design with a front afocal [26], and it has the following advantages: it can answer the high numerical aperture challenge required by microbolometers while having a great flexibility with the field of view and while limiting the unused pixels between the subimages. It only uses conventional components, thus enabling rapid and cost-effective manufacturing and assembling.…”