Abstract:This paper introduces the basic principles of radiation temperature measurement technology and key issues in research. The current application status of temperature measurement methods for engine turbine blades based on infrared radiation at home and abroad is summarized, the errors generated during measurement are analyzed, and the measures to reduce errors are proposed. It is pointed out that in terms of environmental radiation, it is necessary to fully consider the influence of combustion gases and environmental surface radiation, establish accurate reflection models, integrate algorithms, and correct radiation interference errors; In terms of emissivity modelling, emissivity model and non?emissivity model should be established in advance according to specific situations, and machine learning algorithms should be combined to improve measurement accuracy; In terms of optical system design, it is necessary to select appropriate optical materials and coatings to enhance the sensitivity of the system in different environments; In terms of data processing, methods such as neural networks, genetic algorithms, and constraint optimization can be used to minimize errors and improve computational accuracy to the greatest extent possible.

Abstract:In this paper, the mechanism of optical comb in Quantum Cascade Laser (QCL) are discussed, including the way of generating optical comb and the influence of related nonlinear effects (such as four?wave mixing effect) on its operation. The importance of waveguide design for quantum cascade laser is elaborated, and the application prospects of QCL optical frequency comb in mid?infrared and terahertz bands are analyzed. It is pointed out that the design efficiency of optical frequency comb can be increased by improving the theoretical model and explaining the physical mechanism of self?starting harmonic optical frequency comb. The development direction of loop quantum cascade lasers in soliton communication and spectral measurement is prospected.

Abstract:This paper aims to explore the latest research progress in spectroscopic technology and introduce the cutting-edge directions in the field of spectroscopic analysis, represented by metasurface spectrometers and computational reconstruction spectroscopic techniques. Firstly, the paper introduces the principle of metasurface technology, analyzes the advantages of lightweight and ultra?compact metasurface spectrometer, expounds the research status of representative metasurface spectrometers such as folding metasurface spectrometer and multi?focus metasurface spectrometer, and discusses the application prospect of metasurface spectrometer in the fields of disease diagnosis, quality control and information processing. Next, the principle of computational reconstruction spectroscopy is described, the characteristics and research situation of waveguide, spatial, filter coded and detector coded computational reconstruction spectrometers are introduced, and the application potential of computational reconstruction spectrometers in spectrum analysis and chemical research is discussed. Then, the principle and characteristics of metasurface hyperspectral imager based on free shape element and deep learning are introduced, and the advantages of combining metasurface and computational reconstruction spectroscopy are discussed. Last, it is pointed out that the combination of metasurface and computational reconstruction spectroscopy will promote the development of the spectrum measurement field to be more intelligent, portable and multi?functional. It is proposed that the spectral measurement technology can be developed more accurately and efficiently by optimizing spectral image reconstruction algorithm, encoder and photodetector design and manufacturing process in the future.

Abstract:In order to solve the problem of stable trapping of particles in optical tweezers in vacuum, experimental research on parameter feedback cooling of nanoparticle's center?of?mass motion was conducted. In a single beam vacuum optical tweezers system, stable capture and equivalent cooling of SiO₂ particles with a diameter of 200 nm under 3 mPa pressure were successfully achieved. Several methods for equivalent temperature estimation were compared, including the integral method using the extension based on the fitted power spectral density curve（PSD）, the integral method using the truncation based on the fitted PSD curve, and the integral method using the truncation based on the real PSD curve. The last method was selected to evaluate the equivalent cooling temperature of nanoparticles. The experimental results show that the equivalent temperature of the nanoparticle's center?of?mass motion in single axis is cooled to approximately 390 mK in minimum, and the corresponding thermal noise limit can be reduced to about 3.6% of its original value in the ultra?weak force measurement. The research results provide valuable references for the ultra?high sensitivity measurement of physical quantities based on optical tweezers in vacuum.

Abstract:A high?precision ultrasonic thickness measurement system based on the least mean square (LMS) adaptive time delay estimation algorithm was developed, addressing the issue of low accuracy of the existing ultrasonic thickness measurement systems. The ultrasonic transmitting and receiving circuits were designed. The high?speed data acquisition and transmission system based on field programmable gate array (FPGA) was developed. The host computer signal processing software based on MATLAB was developed. The ultrasonic time of flight (TOF) was calculated accurately and efficiently by LMS adaptive time delay estimation algorithm, so as to realize high?precision thickness measurement. The simulated echo simulation experiments were conducted. The results show that the LMS method has more advantages in time delay estimation than the peak method, envelope method and correlation method. An ultrasonic thickness measurement system based on LMS adaptive time delay estimation algorithm was built, and the thickness measurement experiments were performed on gauge blocks. The results show that the relative error of thickness measurement is less than 3.77%, the standard deviation of repeated experiment is not higher than 0.2 μm, and the maximum relative measurement uncertainty is 1.4%. The ultrasonic thickness measurement system based on LMS adaptive time delay estimation algorithm can be applied in the fields such as plate thickness measurement, which is conducive to promoting the development of high?precision ultrasonic thickness measurement technology and has important technical reference value.

Abstract:To solve the problem of task allocation for drone mapping in complex mountainous terrain, a unified solution for multi?drone mapping task allocation / flight path planning was proposed. Firstly, a flight path planning model was established for each mapping area based on the complexity of different terrain in mountainous areas. Then, a unified model for multi?drone mapping task allocation / flight path planning was established with the optimization objective of minimizing the mapping time and flight time between various task points of the drone, and the constraints of the drone's cruising speed and maximum task duration, etc. Finally, the multi?drone mapping task allocation unified model was solved using a distributed genetic algorithm. An experimental verification was conducted to verify the effectiveness of the algorithm, and the results showed that the distributed genetic algorithm significantly reduced the mapping time and improved the mapping efficiency. The research findings provide a new technical approach for drone mapping task allocation and play a positive role in promoting the development of drone mapping.

Abstract:In order to improve the performance of the laser vibrometer LV-400 (Laser Vibrometer, LV) and solve the problem of laser vibrometer being difficult to adapt to harsh operating environments, general quality characteristics were applied to the development of laser vibrometer LV-400. By screening and sorting out the general quality characteristic standards, the core clauses of six characteristics were used to complete reliability identification, temperature, humidity, random vibration, function impact and other tests, and targeted instrument design improvements were made. By adopting a series of corrective measures such as mechanical structure improvement, sealing, gluing, and applying three proof paint, the impact of high temperature, high humidity, and vibration environments on the performance of optical instruments has been effectively overcame. By applying professional knowledge related to the six characteristics, the environmental adaptability of optical devices has been improved, and the range of use of the laser vibrometer LV-400 has been expanded. This type of laser vibrometer can still maintain stable performance in relatively harsh operating environments. The organic combination of general quality characteristics with the development task of laser vibrometer LV-400 has improved the quality and development efficiency of laser vibrator, reduced the burden on researchers, and has important reference significance.