In the field of uncooled Long Wave Infra Red (LWIR) imaging, CMOS compatible bolometers technology is being more and more popular, exhibiting precise temperature measurement at moderate cost. The price of this technology is proportional to the number of components produced per wafer, leading to a shrinkage of the pixel. Enhancing the resolution level of the focal plane array (FPA) requires an improvement of the point spread function (PSF) of the optical system, leading to more and more complex aspheric lenses, and an increased cost of imaging systems. We propose to add a sub-wavelength blade to the existing parts of the imaging system to ease the overall improvement of the image quality in applications with a constraint budget. The main function of such a subwavelength blade should be to control the phase of the light into an optical system to compensate optical aberrations. A cost effective solution consists to make such devices using microelectronics based collective fabrication process. The main difficulty is to predict the subwavelength blade behavior within an optical system that is to say combining millimeter sized optical components that are modeled using ray-tracing or electromagnetic simulations. In this paper we present the results obtained from an effort to simulate, fabricate and characterize all-dielectric subwavelength blade. In an imaging system, our devices will have to deal with non-flat wavefronts. Our method is based on Fourier Modal Method and Angular Spectrum Method to simulate subwavelength optics into such an optical system. Finally, we have compared our simulations results to experiments on basic examples, like spherical aberration correction of a commercial lens.
HgCdTe avalanche photodiodes offers a new horizon for observing spatial or temporal signals containing only a few infrared (IR) photons, enabling new science, telecommunication and defence applications. The use of such detectors for free space optical communications is particularly interesting for both deep space and high data rate links as it enables wide field of view free space optical coupling to the detector at high sensitivity, down to single photon level and with a close to negligible loss of the information contained in the strongly attenuated photon flux. Measurement of the response time and dark current shows that such devices can be operated at room temperature with bandwidths up to 10 GHz in a back-side illuminated configuration. This configuration allows to use micro-lenses fabricated directly into the APD substrate and enables to use a large photosensitive area while maintaining a high bandwidth, low dark current and /or high operating temperature. We report on the expected performance 4-quadrant APD detector demonstrator with single photon sensitivity, which is currently developed to be used in deep space telecommunications by ESA and present the potential use for high data rates links of 10 Gbits/s.