Publications by authors named "Nicolas Fraval"

Liquid crystal (LC) tunable lenses have been extensively studied and used in various applications, however, most of them have been evaluated regardless of their optical imaging quality, in particular, concerning their intrinsic diffuse scattering. In this paper, we investigate the impact of such impairments when LC lenses are used as tunable elements in a depth-from-focus algorithm (DfF). We attempt to analyze these effects in order to design LC lenses that mitigate their impact on the imaging quality.

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Article Synopsis
  • The study focuses on creating and testing modal liquid crystal lenses (MLCLs) that utilize a symmetrical electrode design with a conductive polymer called PEDOT-PSS.
  • The lenses show improved performance, including shorter focal lengths of up to 1cm, smaller apertures ranging from 1 to 5mm, and minimized optical distortions compared to previous models.
  • A key feature is the even distribution of conductivity across the PEDOT-PSS layers, allowing for lenses with short f-numbers and great depths of focus, resulting in enhanced optical quality.
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We present the realization of an electrically tunable wave plate, which uses a nematic liquid-crystal (LC) phase retarder that allows fast and continuous control of the polarization state. This device is built using a quadripolar electrode design and transparent conductive polymer layers in order to obtain a uniform electric field distribution in the interelectrode area. With this realization, we obtain a high degree of control of the orientation of the electric field and, consequently, of the LC director.

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