Driven by the rapid innovation of science and technology and industrial manufacturing technology, virtual reality display technology has developed rapidly. At present, the application of virtual reality display technology is expanding in many fields such as military, medical, aviation and education. This paper analyzes the imaging principle of the human vision system and the optical performance requirements of VR heads-up display, summarizes the current design scheme of VR heads-up optical imaging system, focuses on the principle and index parameters of each optical system, and compares the advantages and disadvantages of different schemes. The development prospects and directions of virtual reality headset displays are also prospected.

Underwater polarization imaging has emerged as a fundamental technique for detecting and imaging underwater targets. However, the effectiveness of this technique is hampered by the low light intensity and optical system deformation induced by water pressure in deep-water environments, particularly for the detection of polarized signals. To address this issue, a wide-field-of-view oil-immersion lens tailored for deep-sea operations is designed, offering robust imaging performance and an extensive observation range. A Mueller matrix is deployed to scrutinize the polarization properties of the entire optical system across diverse fields of view, and the measurement errors in the polarization degree under incident polarization states are discussed. Simulation results demonstrate that the measurement error for linearly polarized light is greater than that for circularly polarized light. Therefore, the system adopts circularly polarized light as the active illumination source, characterized by minimal polarization effects and high detection accuracy. Finally, a deep-sea camera lens is produced and manufactured. The resulting lens is shown to pass a test in a hydrodynamic simulator machine, demonstrating that it can operate properly and capture images.

Conventional cooled infrared optical systems employ a cold stop, which disrupts optical-path symmetry and constrains exit-pupil matching. Consequently, reducing the refractive lens count increases the residual broadband-aberration burden, motivating the introduction of an ultrathin phase-compensation element near the exit pupil. Conventional solutions therefore tend to use complex optical configurations with large volume and high weight, making it challenging to meet the demands of modern lightweight and compact detection systems. Metalenses offer a new approach for aberration correction through the flexible phase manipulation enabled by their unit cells. However, severe chromatic dispersion of metalenses under broadband conditions remains a major obstacle to their practical application. To address this issue, a hybrid refractive–metalens design method for cooled infrared optical systems is proposed. Based on the distinctive phase distribution characteristics of metalenses, an achromatic theoretical formulation applicable to broadband infrared wavelengths is derived. Guided by this theory, a cooled mid-wave infrared refractive–metalens hybrid optical system is designed, featuring a full field of view of 126°, an F-number of 2, and an operating wavelength band of 3.3–5 μm. In comparison with a conventional eight-element refractive system of identical specifications, the proposed hybrid system reduces the total optical-element count from eight to four and achieves reductions of 21% in total track length and 79% in system weight, while maintaining a full-field polychromatic MTF above 0.4 at 33 lp/mm. In addition, the narcissus effect is effectively mitigated under the modeled conditions. This approach enables high-performance aberration correction using metalenses while offering a new design paradigm for simplified infrared optical systems.