In recent years, the application of fisheye lenses has been surging in fields like wide-angle imaging, surveillance, panoramic simulation, dome projection, etc. Compared with other lenses, the fisheye lens has the advantage of providing users with extensive angles of view, but it also has the inconvenience of needing to correct image distortions. In general, there are a large number of scenarios where the advantages of fisheye lenses outweigh the disadvantages of fisheye lenses, hence its widespread usage.
Fisheye lenses can be used to build laser detection systems to realize wide-angle laser detection. Traditional laser detection systems in the past integrate Fabry-Perot interferometers or Michelson interferometers. The former requires a scanning mechanism and therefore cannot detect laser pulses; the latter has a small field of view and a complex structure. The wide-angle laser detection system using a fisheye lens does not require a scanning mechanism and can simultaneously detect the laser wavelength and incident direction.
Fisheye lenses are also an excellent option for monitoring cameras. For example, fisheye lenses built for thermal imaging are a solution to implement panoramic surveillance, realizing scouting with extended fields of view even in poor illumination conditions.
Fisheye lenses can also be used to achieve three-dimensional reconstruction and virtual browsing. By using a fisheye lens with an image of over 180 degrees to take a photo before and after a certain scene, a three-dimensional model can be built, and the user can observe the scene from any angle. Using carrier vehicles such as drones equipped with fisheye lenses to obtain video data, and then converting the video into a sequence of panoramic images arranged in the order of time, a virtual geographical environment model can be established. This large-scale geographical environment modeling technique can be applied to monitoring in firefighting, forestry, and other fields.
Using the diffraction transformation effect of fisheye lenses on a Gaussian beam, a flat-top focused fine laser beam can be obtained. The fine laser beam obtained using fisheye lenses can be used in various fields such as high-precision laser processing and medical treatment.