Using spectrometer technology, we can quickly determine the sugar content in fruits, the protein content in grains, the authenticity of jewelry, the identification of drugs and explosives. Even our Chang'e-1 carried a spectrometer. Without landing on the moon, it could distinguish the substances and ore distribution on the lunar surface through the reflection of sunlight on the lunar surface. Spectrometers seem to have magical powers. Then what is a spectrometer? What is its working principle? When it comes to spectrometers, many of us may feel unfamiliar. In fact, a spectrometer is a device that captures and collects spectral information through the light beams reflected by objects. By using the principle of optical dispersion and modern advanced photoelectric conversion technology, it can determine the elements contained in these objects. Simply put, a spectrometer consists of three systems: a light source, a light splitting system, and a collection system. The light source emits light, which irradiates the object. If the object is a relatively transparent liquid, the transmission method is adopted, allowing the light from the light source to pass through the transparent liquid to generate sample light. If the object is solid or powdery, the diffuse reflection method is used to obtain sample light through reflection on the object's surface. This sample light, after transmission and reflection, already contains the characteristics of the substance. The sample light passes through the light splitting system, and the energy of light at each wavelength can be obtained, which is somewhat similar to the rainbow we are all familiar with or the prism in junior high school textbooks. Finally, a photoelectric sensor converts the light energy into electricity, forming a signal that is recorded. Thus, spectra of different substances can be generated. According to the light absorption characteristics of substances, we can quickly determine what the substance is! There are many types of spectrometers, and there are also many classification methods. According to the principle of spectral decomposition adopted by spectrometers, they can be divided into two categories: classical spectrometers and new-type spectrometers. Classical spectrometers are instruments based on the principle of spatial dispersion (light splitting); new-type spectrometers are instruments based on the modulation principle, so they are also called modulation spectrometers. Spectrometers have a very wide range of applications, and almost all industries have demands for them. A high-quality spectrometer can detect the content of various elements in products with an accuracy of up to 0.001ppm. Generally, enterprises have this demand, as it can help enterprises save costs and improve product quality. Spectrometers are widely used in the research, analysis, and detection of material samples. For example, they are used in fields such as pollutant detection, taste identification, color identification, medical diagnosis, and food production. Among them, the most widely used is the spectral mapping method, which has been widely applied in fields such as pharmaceuticals, biology, environment, and food. The spectral mapping method can be used to analyze elements, compositions, and structures in samples. With its powerful detection and analysis functions, it can quickly locate, diagnose, and identify toxic and harmful substances. Spectrometers can also be used in conjunction with other types of instruments to develop more accurate analysis methods and processes, providing strong support for modern scientific research and industrial production. With the continuous emergence of new technologies, the spectrometer industry is also constantly innovating and developing. In recent years, the miniaturization, intelligentization, and big dataization of spectrometers have become key development directions of the industry. The use of microchips and nano-scale components improves the optical structure, further increasing detection speed and accuracy; new technologies such as big data cloud computing and artificial intelligence have spawned new models of spectral analysis data visualization, and so on. At the same time, the development of new materials and the needs of cutting-edge research in biomedicine, environmental science, etc., have promoted further innovation in spectrometers such as emission, fluorescence, and Raman spectrometers. The world's smallest spectrometer Yang Zongyin, a researcher in the Hundred Talents Program of Zhejiang University, was selected into the "35 Innovators Under 35" for inventing the world's smallest spectrometer and ultra-wide wavelength tunable nanolaser. He pioneered a series of theories, methods, and technological research on full-spectrum light emission and detection based on bandgap graded semiconductor materials, achieving multiple "world firsts". At the same time, he has broken through the core technical bottlenecks in the miniaturization of spectral detection equipment from aspects such as micro-spectrometers, wavelength-tunable light sources, and the synthesis of new luminescent materials, and has carried out industrialization research. Traditional spectral detection equipment is difficult to play an important role on a large scale in fields such as chemical analysis, food testing, and biological testing due to its large size and high price. However, reducing the size of its internal optical and electrical components will lead to a significant decline in its performance, making it inapplicable. Therefore, the miniaturization of spectral detection equipment is a major technical challenge faced by the scientific community. Yang Zongyin was the first to propose a technical scheme for the miniaturization of spectrometers that integrates light splitting and detection, and pioneered the combination of computational spectral technology with semiconductor nanomaterials to develop the world's smallest spectrometer. The size of this spectrometer device is only tens of microns, which is only 1/1000 of that of traditional spectrometers. It solves the scientific problem of achieving large spectral range dispersion at the micron scale and breaks through the challenge that traditional spectrometers cannot have both small size and high performance. The reviewer of Science commented on this research: "This research is a masterpiece combining the world's most advanced material synthesis technology, the highest level of device fabrication and experimental skills, and clever algorithms." The technical barrier of micro-spectrometers is relatively high, and there are no mature products on the market yet. The reconstruction speed of computational spectroscopy is a technical barrier, which requires a lot of innovations in algorithms to solve. It is reported that the current algorithm can reach a speed of 0.1 seconds, which can meet the requirements of spectrometers for single-point measurement, but it is not enough for imaging spectroscopy. Mobile phone sensors are currently in a "bottleneck" state of development. Micro-spectrometers are a "golden track" in the long run, but there are still many technical and application problems to be solved in the short term. "Technology is constantly advancing. I believe that in recent years, with more and more talents entering this industry, the problems of spectral resolution and stability will be well solved," said Yang Zongyin. The world's first tomographic spectrometer In recent years, with the continuous expansion of the market scale, the semiconductor industry has increasingly higher standards for material detection. However, because the current detection methods on the market cannot accurately grasp the structural performance of thin film materials, the development of the chip industry has fallen into a bottleneck. After nearly 10 years of dedicated research, Lu Guanghao, a postdoctoral fellow at the University of Massachusetts Amherst, a national overseas young scholar, and a professor at the Frontier Institute of Xi'an Jiaotong University, finally led his team to achieve a technological breakthrough in 2020. They developed organic thin film tomographic absorption spectroscopy analysis technology, built the world's first in-situ tomographic spectrometer in the laboratory of Xi'an Jiaotong University, and achieved a series of results in supporting software and algorithms. The team breakthroughly used soft plasma source etching technology, and by accurately detecting the tomography of organic semiconductor thin films, turned the "bottleneck" into a "trump card". While filling the gap in the semiconductor market, this technology has forged a key tool for China to break through Western technological blockades. The tomographic spectrometer expands the traditional "one-dimensional spectrum" into a "two-dimensional spectrum", which can characterize the component distribution, condensed state structure, optical distribution, spatial and energy distribution of charge local state density at different depths of the thin film, etc. It provides direct experimental evidence for charge distribution and charge transport in devices, and can be used as an analytical instrument in laboratories of enterprises and research institutions. The main competitors of this product are American Thermo Fisher, Agilent, Japanese Shimadzu and other spectrometer companies, but these companies only have one-dimensional spectrometers and no tomographic spectrometers for sale. Therefore, the tomographic spectrometer and corresponding semiconductor analysis software developed by Professor Lu Guanghao's team are unique and have built technical barriers. At present, Professor Lu Guanghao has established Shaanxi Puguang Weishi Technology Co., Ltd., and in June 2021, received start-up funds from the Qin Chuangyuan Spring Seed Fund. The company has developed a series of products such as PGWS PU-100, PGWS PU-200, PGWS DU-100, PGWS DU-200 around spatial and time-resolved spectroscopy technology, and has completed millions of yuan in equipment sales orders from well-known universities including the University of Chinese Academy of Sciences and Peking University, with more than 100 data users. At the same time, Shaanxi Puguang Weishi Technology Co., Ltd. was successfully selected into the list of science and technology-based small and medium-sized enterprises in the 7th batch of Shaanxi Province in 2022, and successfully entered the finals of the 11th China Innovation and Entrepreneurship Competition Shaanxi Division. With its mature models, supporting analysis and calculation software, patent portfolio layout, the scientific research and entrepreneurship platform of Xi'an Jiaotong University, and the continuous empowerment of the Qin Chuangyuan Spring Seed Fund team, Puguang Weishi is sure to create its own world in the spectrometer market and contribute to "Intelligent Manufacturing in China"! China's spectrometer industry started in the 1950s. After years of intensive development, it has now become a world-leading country in spectrometer manufacturing. In the future, spectrometer manufacturing enterprises need to continuously improve their technical level in R&D and manufacturing, maintain their competitiveness in the international market, and contribute to the development of China's spectrometer industry. Article sources: Robot Engineer, Oriental Flash, DeepTech, Innovative Xi'an