——Li Siyuan, Director of Spectral Imaging Technology Research Office of Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences
More than 2500 years ago, the famous Chinese philosopher Mozi discovered the mystery of small holes forming inverted images; More than 500 years ago, Italian physicist Cardano invented the optical dark box; Over 200 years ago, daguerreotype photography emerged, which is a continuous pursuit and exploration by humans to obtain image information. Nowadays, the emergence of spectral imaging technology integrates spectral detection and imaging techniques, which can simultaneously obtain geometric images and spectral features of targets, achieving comprehensive detection and recognition of target features. It involves technologies such as optics, spectroscopy, precision machinery, electronics, computer signal processing, pattern recognition, and artificial intelligence, and is hailed as a leap in the history of optical instrument development.
Since the research work of spectral imaging technology based on Michelson interferometer was carried out by Xi’an Institute of Optics and Fine Mechanics, Chinese Academy of Sciences in the mid-1980s, the scientific research achievements in the early 1990s have reached the international cutting-edge level. So far, optical imaging technology has developed into a characteristic discipline of Xi’an Institute of Optics and Fine Mechanics, and is in the international leading position in the field of interferometric spectral imaging technology. As a senior engineer at Xi’an Institute of Optics and Fine Mechanics, Director Li Siyuan has served as a project leader or one of the main leaders for the past five years. He has undertaken and successfully completed two major national aerospace engineering payload development tasks, led the breakthrough of multiple key technologies for interferometric spectral imaging, and achieved multiple innovative results, receiving unanimous praise from the overall unit and users.
As the leader of the hyperspectral imaging technology team, Li Siyuan actively leads the layout of innovative research on various spectral imaging technologies such as on-chip spectral imaging, quantum dot spectral imaging, compression encoding, and zero interference cancellation, exploring new mechanisms and approaches for spectral imaging technology, which has received widespread attention from peers at home and abroad. He actively promotes the promotion and application of hyperspectral imaging technology, leading the establishment of research platforms such as Shaanxi Spectral Imaging Engineering Center, Shaanxi Key Laboratory of Optical Remote Sensing and Intelligent Information Processing, Xi’an Key Laboratory of Biomedical Spectroscopy, and Xi’an Spectral Technology Laboratory for Calligraphy and Painting Artworks. He has created an integrated scientific research and development system of “production, learning, research, and application”, making outstanding contributions to the development of hyperspectral imaging technology in China.
Innovative imaging technology is widely used in the industry
Hyperspectral imaging technology has gained widespread attention from scholars both domestically and internationally since the 1990s due to its ability to simultaneously extract two-dimensional spatial information and one-dimensional spectral information of ground targets. Compared to advanced remote sensing countries in the world, China’s optical remote sensing payload technology has developed rapidly in recent years. Some indicators of aerospace optical remote sensing payloads have approached or reached the international advanced level, but overall there is still a gap compared to foreign countries.
The hyperspectral imaging technology team of Xi’an Institute of Optics and Fine Mechanics is a representative and leading research group in the field of spectral imaging technology in China. With the joint efforts of several generations, the team closely follows the national major needs and development priorities, faces the international scientific and technological forefront, and focuses on the national “Eleventh Five Year Plan” to “Fourteenth Five Year Plan” to deeply explore the potential of interferometric hyperspectral imaging technology. The hyperspectral spectrometer is extended from the visible spectrum to the mid to long wavelength infrared band, realizing the productization of full spectrum hyperspectral resolution; Actively promote cutting-edge research in the field of hyperspectral imaging, and advance the theoretical research and engineering development of new spectral imaging technologies such as on-chip spectral imaging, compressed encoding spectral imaging, quantum dot spectral imaging, and zero interference cancellation; We have expanded the application of hyperspectral imaging in cultural relic protection and research, environmental and atmospheric pollution detection, monitoring of water quality in various types of water bodies, and biomedical pathological diagnosis. We have built an internationally leading team for the development of spectral instruments, and the relevant research technology level has reached an international leading position.
In recent years, the hyperspectral imaging technology team of Xi’an Institute of Optics and Fine Mechanics has undertaken and successfully completed the research and development tasks of multiple major national aerospace engineering payloads, such as GF-14 satellite hyperspectral camera and HJ-2 hyperspectral imaging payload. In response to the demand for miniaturization of hyperspectral imaging technology, a small hyperspectral imaging instrument APHIS has been developed, which is easy to achieve large relative aperture, sufficient energy, and high signal-to-noise ratio; Easy to achieve miniaturization, compact structure, small volume, and light weight; Due to its simple structural form, APHIS series products have achieved small batch production with minimal spectral line bending and color distortion. In the current environment of similar products being banned and restricted from purchase abroad, the successful localization and small batch development of APHIS series products will break the monopoly advantage of foreign enterprises.
In response to the problem of water pollution, traditional water quality monitoring systems have shortcomings such as low monitoring frequency, large errors, scattered data, and inability to quickly and accurately reflect pollution conditions. Researcher Yu Tao from Xi’an Institute of Optics and Fine Mechanics led the development of an online water quality detection technology based on spectral sensing, which quickly gained market attention due to its pollution-free nature, high monitoring frequency, and small errors. We have developed a laboratory prototype and made original and original technical reserves for core key technologies such as micro wide spectrum analysis module, full spectrum analysis prediction model, and adaptive calibration technology, mastering the core technologies. Dr. Zhang Pengchang, a member of the hyperspectral imaging technology team at Xi’an Institute of Optics and Fine Mechanics, has led research on the application of hyperspectral technology in cultural relic archaeology, mural restoration, and calligraphy and painting identification in China. He has established a spectral acquisition system for Tang tomb murals and a pigment spectral database, developed a high-resolution image scanner for cultural relics, and a spectral identification system for Chinese calligraphy, painting, and painting. With hyperspectral technology as the core, he provides a wide spectral range and high-resolution spectral information acquisition function. At the same time, through specialized development, he matches the hardware system with a professional database and software system for cultural relic protection, making it truly have non-destructive, intelligent, efficient, and professional cultural relic protection functions. The related products have been applied to Shaanxi Cultural Investment Group, Shaanxi History Museum, and Sanxingdui Cultural Relics Protection Unit. The related products received media coverage such as CCTV13 during the 2020 Canton Fair.
Serve the local economy and assist in industrial upgrading
The development of spectrometers requires the mutual infiltration and innovation of optoelectronic technology and other scientific technologies in application. It is a carrier that integrates the achievements of electronics, optics, machinery, materials and other industries, and can serve various industrial fields such as agriculture, industry, food safety, criminal investigation and security, and medicine. Therefore, the research and development of spectrometers can not only drive the development of the manufacturing industry, but also promote the prosperous development of high-tech industries such as electronic component manufacturing, electronic information, and optoelectronics. Spectrometers, with their rich functions and high efficiency advantages, have gradually formed a new industry development model of “point to area”, indirectly promoting the development of related industries and promoting the rapid growth of social productivity.
At present, Wu Qijing, a member of the hyperspectral imaging technology team at Xi’an Institute of Optics and Fine Mechanics, has led the establishment of Xi’an Zhongke Yingte Spectral Technology Co., Ltd., specializing in the research and development of various hyperspectral instruments and equipment, instrument calibration, hyperspectral data acquisition, and technology promotion and application. Its spectral imaging products and fine spectral detection technology are widely used in fields such as security, medical, petroleum, scientific research, archaeology, environmental protection, atmospheric meteorology, environmental monitoring, and food safety.
So far, the company has 5 core patents and 6 software copyrights, and has been awarded honors such as “National High tech Enterprise”, “ISO Quality Management System Certification”, “Intellectual Property Certification Enterprise”, and “Shaanxi Private Technology Enterprise”. At the same time, as a co builder of “Shaanxi Spectral Imaging Engineering Center (Science and Technology Department)” and “Shaanxi Spectral Imaging Engineering Technology Center (Development and Reform Commission)”, the company has unique advantages in technology reserves, support, and transformation.
With the rapid transformation of related products by the company, expanding the domestic market, solving livelihood problems, and enhancing the overall technological level of the optical imaging industry in Shaanxi Province. Relying on the positioning of the “the Belt and Road” and the international logistics port in Xi’an, it has made important contributions to the economic and social development of Shaanxi Province by integrating scientific research resources, improving innovation ability, expanding the market of spectrometer products, expanding product scale, and forming economic growth points.
Li Siyuan stated that future research will cover important issues related to the acquisition and application of hyperspectral data, closely related to the current major development needs of the country. By exploring the potential of interferometric spectral imaging technology and promoting the development of various new spectral imaging technologies such as on-chip spectral imaging technology, compressed encoding spectral imaging technology, quantum dot spectral imaging technology, etc., it can effectively solve the information acquisition difficulties faced by China in scientific research, national defense construction, resource development, and other aspects in different application environments and even extreme application environments, achieve all-weather optical target information acquisition, and realize the leapfrog development of optical remote sensing payload equipment from “visible” and “clear” to “understandable”. The research on calibration and data quantification technology for optical remote sensing instruments will solve the problems of limited application efficiency of hyperspectral remote sensing data, such as difficult remote sensor radiation traceability, poor accuracy, large attenuation changes, and poor radiation consistency among multiple remote sensors.
In the civilian field, through in-depth research on new spectral imaging technology, they will effectively break the foreign monopoly in the spectral imaging market, explore the domestic market, solve people’s livelihood problems, and enhance the overall technical level of China’s optical imaging industry. Make full use of the development opportunities of the “the Belt and Road”, take the market as the guide, take the spectral imaging instruments as the main line, focus on breaking through the problems of low cost, high performance, high reliability, miniaturization and other problems of instruments, focus on internal and external connection, and embark on the virtuous circle development path of combining industry, university and research.
The road to chasing light is long and arduous, and we are not afraid of difficulties to face them. Faced with the long road ahead, Li Siyuan and his team will continue to explore and innovate. On the road of chasing light, we will break through the limits of spectral imaging technology, bring more advanced scientific research achievements, and serve industry applications, achieving greater social and economic benefits. (Written by Wang Chao)