Abstract:Based on a brief introduction to the basic principles and equipment involved in picosecond laser dicing, the characteristics of some materials often involved in the packaging of infrared focal plane array modules and their action mechanisms to the picosecond laser beams are reviewed. By optimizing the laser parameter settings, the dicing efficiency is improved and the dicing quality is guaranteed; by improving the clamping apparatus, metal layer damage is avoided and the operation convenience is improved.

Abstract:The preparation of high-quality indium antimonide (InSb) single crystal is the key to the development of large-format infrared focal plane devices and new substrate materials for high-temperature infrared detectors. However, in the process of growing InSb by the Czochralski method, the appearance of surface impurities will seriously affect the yield. The X-ray photoelectron spectroscopy (XPS) technology is used to study the composition of the impurity layer on the surface of InSb crystals in production, the main sources and their effects are analyzed, and corresponding process measures are adopted to improve them. The results show that the main components of the impurity layer on the surface of InSb crystals are a mixture of In₂O₃, Sb₂O₃ and Sb₂O₅ as well as carbon contamination, the thickness of which is not more than 40 nm. By optimizing the processing of the single crystal furnace treatment and the protective atmosphere, the surface impurities are greatly reduced, laying the foundation for obtaining high-quality crystals.

Abstract:The application, design and preparation of a 2.06 μm laser polarizing film in the near-infrared solid-state laser are introduced. Based on the basic theory of thin-film optics and the comparison of three different membrane structures, the initial membrane structure is determined. Relevant technical issues such as film selection, pass-band ripple compression, and process preparation are discussed. The membrane structure is repeatedly optimized by computer optimization software. The polarizing film is prepared by electron beam vacuum evaporation and ion source assisted deposition, and its spectral detection is performed. Then, the relevant parameters in the preparation process are optimized according to the test results. Finally, the laser polarizing films with excellent optical properties, low film absorption, good uniformity and high stability are prepared.

Abstract:The main beam of the conventional lateral detection antenna is perpendicular to the radiation surface of the antenna, which will result in a high false detection rate of flight detection. Therefore, it is necessary to study the antenna with forward tilt detection function in order to improve the detection accuracy. Based on HFSS software, a slit antenna structure was designed. The input parameters of the design were in the frequency band 36.85-37.15 GHz, the isolation between transmitter and receiver was better than 50 dB, the forward inclination angle was 20°-24°, the side lobe suppression was more than -10 dB, the antenna length was less than 85 mm, the azimuth angle was more than 80°, and the horizontal angle was less than 11°, the gain was more than 11 dB. The test results show that the gain is 12 dB. Under the condition of 36.85-37.15 GHz, the azimuth angle is between 116°-134°, the pitch angle is between 8°-9°, the forward tilt angle is between 22°-24°, the side lobe suppression is ranged from -11.45 dB to -14.60 dB, and the beam direction is controllable. In the frequency range of 36.5-37.5 GHz, the standing wave ratio(SWR)is kept below 1.413, the isolation between transceiver and receiver is kept below -51-132, and the total antenna length is 83 mm. The test results are consistent with the design, which can meet the design requirements, and provide antenna technical support for the UAV′s lateral detector.

Abstract:In the fabrication process of GaAs integrated passive device (IPD), via-hole etching is an important link. GaAs at the edges of the etched holes is etched, which can cause chipping and adversely affect device performance and reliability. In this paper, the thickness of GaAs for via-hole etching is not less than 200 μm, and the edges of the via-holes are not etched to achieve smooth connection of metal wires. The photoresist and metal are used as a mask to effectively solve the problem that the single photoresist is deformed due to excessive thickness or a thin thickness causes the GaAs substrate to be etched. By optimizing the process, under the conditions of a photoresist thickness of 32 μm, a metal mask thickness of 0.5 μm, a metal etching time of 60 s and an inductively coupled plasma (ICP) etching of 4000 s, the morphology of a hole depth of 200 μm and a flat via-hole edge are obtained. The main reason and mechanism of GaAs chipping are analyzed, and the chipping problem of 200 μm via-holes is solved by the optimized process, thereby improving the device performance and reliability.

Abstract:In the case of GPS signal loss of the unmanned aerial vehicle (UAV), the auxiliary visual recognition accuracy of the test pile is a key factor affecting the automatic inspection of oil and gas pipelines. Aiming at the accuracy problem of automatic identification of test piles, based on the analysis of the background and target characteristics of the test piles and surrounding objects, a deep learning algorithm was used to determine whether the test piles were obscured by the surrounding objects. For obstructed test piles, the relative location algorithm of the insignificant target was used to detect the specific position of the test piles. Finally, the validity of the algorithm in this paper is verified by actual test scenarios experiments.

Abstract:The purpose of this study is to explore the characteristics of infrared heat maps in patients with insanity and to lay the foundation for the application of infrared thermography detection technology in the diagnosis of insanity. Using a simple random sampling survey and a comparison method, a total of 600 people′s infrared heat map data was collected. The ratio of the number in the crazy group to the number in the normal group was 5∶1. Syndrome classification was performed on patients with insanity. Infrared thermal imaging data collection was performed for all subjects. The relative temperature differences (ie ΔT) of 15 areas including upper coke, middle coke, lower coke, governor meridian, ren meridian were detected, and paired-samples T tests were performed. The results showed that 91.6% of the patients with insanity had deficiency syndromes. Compared with the normal group, the ΔT in the four measurement areas of upper coke, governor meridian, virtual and right flank was significantly different (P <0.05). Among them, the ΔT of upper coke, governor meridian and virtual for the epileptic patients was lower than that of the normal people, while the ΔT of the right flank was higher than the normal people. The majority of patients with clinical epilepsy have deficiency syndromes. As an objective evaluation index of non-invasive functional images, infrared thermal imaging has clinical application value in the diagnosis of insanity.

Abstract:In order to observe the infrared body surface temperature changes of related meridian acupoints in insomnia patients, the body surface temperature of the acupoints on Du meridian, bladder, spleen, heart channel and yinqiao, yangqiao meridian of insomnia patients and healthy volunteers was collected by an infrared human skin temperature rapid screening instrument. The temperature difference in the same name acupoints of the two groups(underarm temperature-acupoint temperature) was compared. The results showed that the temperature of the back and neck points on Du meridian and bladder in the insomnia group decreased more significantly than the control group (P <0.05). Although the temperature of the spleen meridian points decreased, there was no significant difference compared with the control group. In the heart meridian of the acupoints, the temperature decreased in some cases and increased in some cases, which was significantly different from the control group (P <0.05). The temperature of leg points on yinqiao meridian decreased (P＜0.05), and the temperature of head points on yangqiao meridian increased (P＜0.05). It can be seen that the changes of body temperature in the meridians of the insomnia patients reflect the intrinsic pathogenesis of insomnia: “the Yang Hyperactivity is on the upper side, the yin is lower than the lower, the yang is not in the yin”. The clinical treatment can be selected according to the results of infrared thermography.