Insect compound eyes are optical systems with small volume and a compact structure. The ommatidia in the dorsal rim area of some insects have polarized vision, which can perceive the polarization pattern of the sky and provide them with navigation information. In this paper, inspired by the polarization-sensitive compound eyes of insects, a bio-inspired polarization navigation sensor based on artificial compound eyes is designed. The sensor consists of an artificial compound eye, an integrated polarization detector and an integrated circuit. The optical path of the sensor uses the lens defocus method, which can ensure that the sensor obtains redundant polarization information. The integrated polarization detector is used to obtain the polarization information of the incident light, and the integrated circuit is responsible for the calculation. To extract effective information from images, we propose a multi-threshold segmentation method to filter and classify effective pixels. We use the least squares method to fit the inherent error of the sensor and then compensate it. The indoor calibration accuracy of the sensor is ±0.3°, and the outdoor calibration accuracy is ±0.5°. The sensor can provide accurate direction information for general smart mobile devices. The size of the sensor is 4 × 4 × 2 cm, and the weight is only 15 g. The key components of the sensor can be mass-produced, and it is a miniaturized and low-cost polarization navigation sensor.

This article studies the measurement error model and calibration method of the bio-inspired polarization imaging orientation sensor (BPIOS), which has important engineering significance for promoting bio-inspired polarization navigation. Firstly, we systematically analyzed the measurement errors in the imaging process of polarized skylight and accurately established an error model of BPIOS based on Stokes vector. Secondly, using the simulated Rayleigh skylight as the incident surface light source, the influence of multi-source factors on the measurement accuracy of BPIOS is quantitatively given for the first time. These simulation results can guide the later calibration of BPIOS. We then proposed a calibration method of BPIOS based on geometric parameters and the Mueller matrix of the optical system and conducted an indoor calibration experiment. Experimental results show that the measurement accuracy of the calibrated BPIOS can reach 0.136°. Finally, the outdoor performance of BPIOS is studied. Outdoor dynamic performance test and field compensation were performed. Outdoor results show that the heading accuracy of BPIOS is 0.667°.

Multilayer coatings induce a significant polarization aberration in optical systems with high numerical aperture (NA) and wide field of view, which will cause wavefront distortion and imaging degradation. Studies have used low-polarization coatings (LPC) design to reduce the coating-induced polarization aberration. However, the polarization aberration caused by LPC remain evident in systems with large incident angles and many coated surfaces. In this paper, a hybrid optimization algorithm (HOA) is proposed to enhance the design accuracy of LPC. Based on the HOA, a collaborative optimization method is developed to simultaneously design coatings with different polarization properties for multiple surfaces, which can correct polarization aberration by mutual compensation between the coated surfaces and other optical elements in a single system. Finally, a high NA lithographic lens is simulated as an example to verify the collaborative optimization method. The simulation demonstrates that this method is superior to conventional methods. This research provides a new way to correct the polarization aberration and is applicable to any systems coated with multilayer coatings.

The polarization perception sensitivity of the human eyes affects the perceived polarized image quality. In this paper, we used polarized spatiotemporal structured images to develop a spatiotemporal age mapping of the polarization perception of human eyes. We built an optical modulation transfer function mathematical model of the aging human eyes with spatiotemporal frequency domains and introduced the Stokes vector to analyze the polarized images. The proposed model provides a testing method based on a set of polarization images with spatiotemporal frequencies varying according to the perception of differently aged viewers. Then, we experimentally validated the proposed model by performing polarization perception tests on a group of volunteers. The test method has the diagnostic potential to confirm the health of human eyes and identify potential age-related macular diseases.

Wavelength is an essential factor affecting polarization propagation. We investigate the polarization persistence of linearly polarized light from ultraviolet to near-IR in foggy environments. Certain spectral bands, from ultraviolet to IR wavelengths that exhibit lower path loss, were initially selected. Using polarization-tracking Monte Carlo simulations for varying particle size, wavelength, refractive index and detection range, it is shown that linear polarization exhibits different persistence performance at different wavelengths in various foggy environments. For wet haze of 0.6 µm or 1 µm droplets, parallel polarization increases persistently as the wavelength increases, and has superior persistence in the near-IR region. For radiation fog of 5 µm or 7.5 µm droplets, parallel polarization shows superior persistence in the ultraviolet region. For advection fog of 15 µm or 45 µm droplets, parallel polarization shows a superior persistence in the ultraviolet region. It is therefore shown that changing the wavelength can improve linear polarization persistence in foggy environments.