Terahertz light field imaging is also known as computational imaging, and its acquisition is limited to terahertz camera scanning. Camera scanning light field imaging systems are limited by the performance of the device, and there are problems such as large image noise and small field of view. This paper proposes a single-camera terahertz light field imaging, using Matlab software for system simulation and image processing, reducing output image noise by adjusting simulation parameters, improving image quality, and browning the image to make the outline clearer. Further analysis of the improvement in imaging quality lays the foundation for the development of terahertz light field imaging in refocusing and depth estimation. Finally, it is pointed out that the terahertz band has strong penetrating power in imaging and can play a unique advantage in biometrics, military detection and security.
Light field microscopic imaging technology is achieved by inserting a micro-lens array capable of capturing light field information on the relay image plane of a conventional optical microscope. The multi-focus surface can be extracted by the refocusing technique to increase the geometric depth of field. The terahertz wave has many advantages, such as strong penetrating power, low photon energy , good coherence and so on. Therefore, It can be used for microscopic imaging to obtain more comprehensive information, and can also improve the depth of field and resolution of imaging, and is also suitable for the detection of living organisms. Based on the principle of light field microscopic imaging and terahertz microscopic imaging technology, this paper analyzed the depth of field is related to the wavelength of the light source and the size of the micro-lens array. It has been found that the depth of terahertz light field microscopy technology can be increased by at least one to two orders of magnitude when the wavelength range is extended to the terahertz band.
Compared with traditional imaging, optical field imaging records the four-dimensional position information and direction information of the object. It has two degrees of freedom more than the two-dimensional traditional image, so it has more abundant image information in the later processing. According to Levoy's theory of light field rendering, light field can be parameterized by two parallel planes. Compared with visible light, terahertz has the characteristics of long wavelength, strong penetration and low energy. Therefore, terahertz optical field imaging technology will have the advantages of wide dynamic range and deep field. This paper summarizes the acquisition methods of light field and describes the post-processing methods of light field, including digital refocusing, super-resolution, depth estimation, synthetic aperture imaging and microscopic imaging technology. Finally, the application of terahertz optical field imaging and the possible problems are summarized.