Image haze removal has attracted much attention in optics and computer vision fields in recent years due to its wide applications. In particular, the fast and real-time dehazing methods are of significance. In this paper, we propose a fast dehazing method in hue, saturation and intensity colour space based on the polarimetric imaging technique. We implement the polarimetric dehazing method in the intensity channel, and the colour distortion of the image is corrected using the white patch retinex method. This method not only reserves the detailed information restoration capacity, but also improves the efficiency of the polarimetric dehazing method. Comparison studies with state of the art methods demonstrate that the proposed method obtains equal or better quality results and moreover the implementation is much faster. The proposed method is promising in real-time image haze removal and video haze removal applications.

Polarimetric dehazing methods have been proven to be effective in enhancing the quality of images acquired in turbid media. We report a new full-Stokes polarimetric camera, which is based on the division of aperture structure. We design a kind of automatic polarimetric dehazing algorithm and load it into the field programmable gate array (FPGA) modules of our designed polarimetric camera, achieving a real-time image haze removal with an output rate of 25 fps. We demonstrate that the image quality can be significantly improved together with a good color restoration. This technique might be attractive in a range of real-time outdoor imaging applications, such as navigation, monitoring, and remote sensing.

In recent years, the thriving satellite laser communication industry has been severely hindered by the limitations of incompatible modulation formats and restricted Size Weight and Power (SWaP). A multi-modulation compatible method serving for free-space optical (FSO) communication has been proposed assisted by chirp-managed laser (CML). The corresponding demonstration system has been established for realizing free-switching between intensity (OOK) and phase modulation (RZ-DPSK). The feasibility and performance of system have been evaluated sufficiently when loading with 2.5 and 5 Gbps data streams, respectively. Additionally, a control-group system has been operated utilizing Mach-Zehnder modulator (MZM) for comparison between CML-based and MZM-based compatibility solutions. The OOK receiving sensitivities of CML-based system are −47.02 dBm@2.5 Gbps and −46.12 dBm@5 Gbps at BER of 1×10−3 which are 0.62 dB and 1.11 dB higher than that of MZM; the receiving sensitivities of RZ-DPSK are −50.12 dBm@2.5 Gbps and −47.03 dBm@5 Gbps which are 0.79 dB and 0.47 dB higher than that of MZM respectively. Meanwhile, CML-based transmitter abandoned the traditional modulator and its complicated supporting devices which can effectively contribute to the reduction of SWaP. The CML-based system has been proven to have the compatibility between intensity and phase modulation while also possesses a miniaturized design. It may provide fresh thinking to achieve a practical miniaturization system for satisfying the requirements of space optical network in future.

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