Infrared detectors are indispensable in the civilian, military, and aerospace fields, and their future develop- ment is of great strategic significance. This paper reviews the history and current status of infrared detectors, focusing on traditional photon-type infrared detectors such as mercury cadmium telluride (HgCdTe), indium gallium arsenide (InGaAs), antimonides, quantum wells (QWs) and silicon-based blocked impurity band (BIB) detectors. It also covers novel detectors, including colloidal quantum dots (CQDs), two-dimensional (2D) material detectors, electro- magnetic induced well (EIW) effect detectors, and ferroelectric polarization-regulated infrared detectors. Additional- ly, it discusses the applications of new technologies in infrared detection, such as event-based dynamic vision sens- ing, computational imaging, absorption enhanced micro/nanostructures, and three-dimensional (3D) integration. Fi- nally, it explores future development trends of infrared detectors.

Room temperature infrared photoelectric detection is an extreme operation condition and remains a great challenge due to strong background radiation influence on narrow bandgap semiconductor. Herein, we report a high performance of room-temperature mercury cadmium telluride (HgCdTe) photoconductive detector based on electromagnetic induced well (EIW) effect mechanism, where non-equilibrium carriers injected from metal electrodes induce variations in the bulk resistance of the MCT sensing element by incident infrared light, thereby enabling sensitive photoelectric detection. The detector achieves a responsivity (RV) of 2.5 × 104 V·W−1 and a noise-equivalent power (NEP) of 0.8 × 10–12 W·Hz−1/2 at 600 μm by integrating a micro-sensing element with a square-spiral coupling antenna mounted on an extended silicon hemisphere using quasi-optical coupling mode. It exhibits a significantly enhanced response with increasing wavelength and successfully realizes high-sensitivity detection in the approx. 300–1000 μm band at room temperature. Our findings suggest that the EIW-based MCT detector breaks through the cryogenic bottleneck of photon-type detectors operated in the far-infrared region, paving the way for high performance of spectroscopic imaging and next-generation communication technologies, with broad prospects in spectral analysis, remote sensing, and non-destructive testing.

Compared to the traditional flip-chip bonded focal plane array, in high-density vertically integrated photodiode (HDVIP) focal plane technology, the thickness of the mercury cadmium telluride (MCT or Hg1-xCdxTe) layer serves as a more critical parameter. This parameter not only influences the efficiency of photon energy absorption but also defines the pn junction area, thereby affecting the magnitude of the dark current. Furthermore, it significantly impacts the manufacturability of via-hole etching and formation processes. This paper investigated the photonic crystal resonances and coherent perfect absorption (CPA) effect of a thin MCT layer in HDVIP by using COMSOL Multiphysics® 4.3b and optimized the structure of the loop-hole photodiode device. The CPA, which is formed by this structure, achieves high absorption of illumination in a very thin MCT film. It is demonstrated that an absorption rate of infrared radiation of more than 95% with a wavelength during the 8 µm-10 µm range can be achieved in Hg1-xCdxTe (x = 0.225) with a thickness of only 1.5 µm-3 µm. The benefit of thinner MCT film is that it decreases the dark current of pn junction and reduces the technical difficulty of etching and metallization of the loop-hole photodiode.

Low noise is a key requirement of readout integrated circuit (ROIC) in hyperspectral applications for its low radiation. Correlated double sampling (CDS) is commonly used to suppress noise. In this paper,CDS is improved by adjusting the time interval between the clamp and sample-and-hold (SH), which can filter low-frequency noise flexibly. A 640x512,15 mu m pixel pitch ROIC is designed and fabricated in 180 nm CMOS process. The input stage consists of low-noise capacitive trans-impedance amplifier (CTIA) and CDS with adjustable intervals (AICDS). A timing generator is proposed to extend the CDS reset time from 0 to 270 clock cycles. By extending the reset time to decrease the time interval, the noise electrons are significantly decreased from 39 e(-) to 18. 3 e(-). The SPECTRE simulation and the experimental results corroborate that the proposed structure AICDS can optimize noise performance of hyperspectral ROIC,thus can be widely used.

An important branch of the three-generation infrared focal plane is high operating temperature (HOT) infrared detector. For HgCdTe n-on-p detectors, dark current can be suppressed with n'-n --p structure and good passivation, and then better performance of the detector will be obtained under high operating temperature. Based on the junction formation simulator, the junction formation parameters of HOT device are achieved and combined with the manufacture technology of optimized passivation layer, HgCdTe n-on-p infrared focal plane arrays which can operate at higher temperature was made in Shanghai Institute of Technical Physics(SITP). The performance of was studied at high operating temperature. One of mid-infrared detector has reached good performance under different operating temperature. The NETD is 6. 10mK and operability is 99. 96% at 80K, and the NETD is 11. 0mK and operability is 99. 50% at 150K , which reached the theoretical limit.

This paper presents an extended short-wave infrared (eSWIR) image sensor, a large format infrared focal plane array (IRFPA), applied in advanced hyperspectral imager (AHSI) aboard China’s three GaoFen-5 satellites and two more followed ZY-1 satellites. Hyperspectral imaging has been emerged as a very important application in Earth observation instruments, for the spectral detection provides the spectrum information of ground objects except for the spatial imaging of the objects. AHSI has a 60-km swath width and a 30-m spatial resolution, and has high signal-to-noise ratio (SNR) in spectrum of interest. Large format infrared focal plane arrays which are ordinarily used in staring infrared imaging have some special performance requirements when applied in hyperspectral imaging, such as higher quantum efficiency, lower dark current, lower noise and selectable current conversion gain to match the different radiation flux of different subdivided spectral bands. We developed a format of 2048×512 HgCdTe/Si IRFPA sensor (equivalent 2012×256 after pixel overlapping and binning) in which 2012 pixels meet the demands of 60km swath width and 256 pixels line meet the 200 spectral bands. The sensor has 8-level gains selectable by spectral bands, and array dark current densities on an order of 10 -10 A/cm 2 , quantum efficiency exceeding 80%, and the operability of 99.5% at operating temperature of around 110K. The SNR of this FPA achieved 150 when illuminated under 5×10 4 photons/pixel.

Objective High dynamic range(HDR)is an important requirement of the advanced Infrared Focal Plane Array(IRFPA).It is limited by the small electric charge capacity and noise of readout integrated circuit(ROIC).One of the common strategies to expand electric charge capacity is well capacity adjusting based on selectable integration capacitors.The other method is multiple sampling implemented by analog-digital converter(ADC)in conjunction with time delay and integration(TDI)technique.However,capacitors and ADC occupies large area,and TDI causes low frame frequency.Correlated double sampling(CDS)is commonly used to reduce low-frequency noise and KTC noise.Nevertheless,the fold effect of CDS due to large-signal saturation,which leads to wrong readout of large-signal,lacks analysis and elimination.Therefore,it is necessary to propose a new structure to enhance the charge capacity in small pixel area and incorporate CDS guaranteed large-signal readout.For this purpose,an adaptive-gain ROIC(AGROIC)integrated with anti-fold CDS(AFCDS)is designed in this paper. Methods The AGROIC and AFCDS is constructed in this paper.AGROIC is accomplished by CTIA in parallel with a MOSFET Mag whose gate voltage is adjustable(Fig.2).The small-signal is integrated through a large-gain CTIA with small capacitor,while the large-signal is injected through the MOSFET,which convert CTIA to RTIA.The conversion gain of ROIC is transformed from the ratio of time to integral capacitance to the reciprocal of the transconductance(Fig.3).The CDS fold effect is caused by saturation of input signal(Fig.7).A fully-passive CDS connected with a MOSFET switch Maf is combined with AGROIC to suppress noise of small-signal(Fig.8).In contrast,the switch turns on in response to large-signal resulting in direct injection to the sampling capacitance(Fig.9). Results and Discussions The proposed AGROIC and AFCDS are integrated in 15µm pixel pitch,designed in 180 nm 3.3 V CMOS process.The simulation results demonstrate the aforementioned analysis(Fig.4,Fig.11).A 640×512 FPA ROIC is designed and fabricated,which consists of AGROIC-AFCDS input stage,control register,time sequence generator,column buffer,multiple outputs,etc.(Fig.12-13).The tests of the designed system are based on an IRFPA testing platform combined with signal generation,clock generation,voltage source,LABVIEW software and signal acquisition(Fig.15).The noise electrons are significantly decreased to 17 e-because of the CDS in pixel(Fig.17).The conversion relationship between injection current and output voltage extremely decreases when the input signal is large enough to turn on Mag,which increases the charge handle capacitance to 1.6 Me-under finite output swing(Fig.18).Therefore,the dynamic range of this circuit is improved to 99.66 dB.Besides,the testing results present the fold effect on condition of turning off Maf and improper gate-voltage setting(Fig.19).The appropriate setting can eliminate the CDS fold effect. Conclusions A 640×512,15µm pixel pitch ROIC incorporated with adaptive-gain ROIC and anti-fold CDS is designed and implemented.A new approach to realize gain adaptation is proposed as follows.The ROIC automatically converts from high-gain CTIA to low-gain RTIA depending on the magnitude of the signal,which ensures high sensitivity readout of small-signals and expands the detection range.The design is suitable for complex small-signal application,such as hyperspectral imaging applications with weak radiation and large differences between elements.The design requires small integration capacitance and can be applied to smaller pixel area.Besides,the fold phenomenon of CDS under large signal is analyzed,and a concise solution is proposed.The designed AGROIC-AFCDS eliminates the fold effect of CDS,suppress the noise to 17 e-,expands the maximum detectable charge to 1.63 Me-,and improves the dynamic range to 99.66 dB.It is a new method to realize HDR in small pixel area which can adapt to the advanced infrared focal plane technology.

: In this paper, , we report research results of 1 280x1 024 dual-color mid-wavelength infrared InAs/GaSb super- lattice focal plane arrays. The detector structure is PN-NP epitaxial multilayer and the signal is read out by sequential mode. The superlattice structure was grown on GaSb substrate using molecular beam epitaxy (MBE ) technology. The respective structures of each absorption region are Mid-Wavelength 1(MW1): (MW1 ): 6 ML (InAs ) /7 ML (GaSb ) and Mid- Wavelength 2 (MW2 ): 9 ML (InAs ) /7 ML (GaSb ). The pixel center distance of the detector is 12 mu m. At 80 K mea- surements, , the detector has spectral response wavelength of 3-4 mu m and 3. 8-5. 2 mu m respectively. The MW1 detector has a peak detectivity of 6. 32x10(11) cmHz(1/2)W(-1). The MW2 detector has a peak detectivity of 2. 84x10(11) cmHz(1/2)W(-1). In- frared images of both wavebands have been taken using infrared imaging test by adjusting the device voltage bias. It's 's the first time that a 1 280 x 1 024 InAs/GaSb Type II superlattice mid-wave length two-color infrared focal plane detec- tor has been in China.

In this paper, the research results of 12. 5 mu m long-wavelength infrared InAs/GaSb superlattice focal plane ar- rays were reported. The superlattice structure was grown on GaSb substrate using molecular beam epitaxy (MBE) tech- nology. The respective structure of absorption region is 15ML ( InAs) /7ML ( GaSb). The detector adopts PB pi BN dou- ble barrier structure to suppress the dark current. A long-wave focal plane detector with the size of 1 024x1 024 and the pixel center-to-center distance of 18 mu m was developed. The detector was packaged by a metal dewar, and a superlattice long-wavelength detector cryocooler assembly was formed by coupling with a refrigerator. Measured at 60 K, the detec- tor has 50% cut-off wavelength of 12. 5 mu m. The detector has a peak detectivity of 6. 6x1010 cm center dot Hz1/2/W , dead pixels rate of 1. 05% and a noise equivalent temperature difference (NETD) of 21. 2 mK. The infrared images have been taken clearly using this infrared imaging detector.

HgCdTe electron avalanche photodiodes (e-APDs) with single-carrier multiplication hold great promise for weak signal detection. This work investigates the key metrics that affect the signal-to-noise ratio of mid-wavelength infrared (MWIR) Hg0.7Cd0.3Te e-APD: current, gain, and excess noise factor. The gain is over 1000 at -10 V, but the maximum useful gain is limited by the generation of band-to-band tunneling current at higher bias voltages. The gain dispersion obtained by characterizing the focal plane array is 4.7% at -7 V, indicating a relatively homogeneous gain from pixel to pixel. The excess noise factors evaluated by the noise power spectral density and the gain fluctuation methods both range from 1 to 1.32 at gains below 400, demonstrating the property of near excess-noise-free amplification of HgCdTe e-APDs.

混合飞行时间测距基于间接飞行时间测距的原理,同时结合直接飞行时间测距的概念,可以实现高精度、高范围的脉冲激光测距.采用两相采集方式,建立了背景光抑制的两段两相混合测距模型,并通过对模型的误差分析确定了电路的相关参数.采用在线性模式下工作的雪崩光电二极管(Linear-Mode APD,LM-APD)作为探测器,设计了与混合测距模型适配的 50 μm中心距的像素电路以及 5×5 阵列结构.电路输入级采用电容反馈跨阻放大器结构,输出信号包括模拟信号和低压差分信号.在对APD探测器 20 MHz的调制频率下,输出电压达到 99.8%以上的线性度,在 108.75 m测距范围内达到 4.415 cm的平均误差,11.355 cm的最大误差.仿真表明:混合测距兼顾精度和测量范围,适用于激光雷达三维成像领域.

Significance Single-photon counting has great application prospects in weak signal detection and time ranging.Since the first photon counting system in the visible spectrum was developed in the 1970s, in order to fully amplify the photon signal and reduce the readout noise of electronic equipments, many groups in the research field are constantly developing and improving the photon counting techniques. Electron multiplying charge coupled devices（EMCCDs） can replace the traditional visible light photon counting system and have higher quantum efficiency. While due to large avalanche noise, accurate acquisition of incident photon number under multiplication is difficult. The excess noise factor of mercury cadmium telluride avalanche photodiode（HgCdTe APD） is close to 1, there is almost no excess noise. Compared with the Geiger mode avalanche photodiodes, the linear mode HgCdTe APD has no dead time and after pulse, does not need to quench the circuit, has ultra-high dynamic range and adjustable spectrum with wide response range. Its detection efficiency and false count rate can be independently optimized. It opens up a new infrared photon band counting imaging application. It is of great value in astronomical exploration, laser radar, free space communication and other applications.Progress Raytheon and DRS Technologies in the United States, CEA/LETI Laboratory and Lynred in France, and Leonardo in the United Kingdom have successively realized single photon counting of linear HgCdTe APD detectors. This paper summarizes the technical routes and research status of linear mode photon counting HgCdTe APD detectors in Europe and America. The performance of HgCdTe APDs, photon counting ability and the advantages and disadvantages of detector preparation with three structures, namely, separation of absorption and amplification（SAM）, planar PIN type and high density vertically integrated photodiode（HDVIP）, are analyzed.Raytheon Company has prepared SAM short-wave HgCdTe APD detectors with hole multiplication mechanism by molecular beam epitaxy（MBE）, with gain of 350, photon detection efficiency of more than 95% and operating temperature of more than 180 K. DRS Technologies has prepared an electron-multiplication HDVIP medium wave HgCdTe APD detector using liquid phase epitaxy（LPE） material. The detector can respond in the visible to mid-infrared band from 0.4 μm to 4.3 μm, with the highest gain up to 6 100 and the photon detection efficiency greater than 70%. It can realize free space communication of 110 Mbps data transfer. CEA/LETI Laboratory and Lynred Company have prepared PIN-type short-wave and medium-wave HgCdTe APD detectors with electron multiplication mechanism by molecular beam epitaxy or liquid phase epitaxy. The gain of short-wave detector is up to 2 000, the maximum gain of medium-wave is up to 13 000, the internal photon detection efficiency is up to90%, the free space communication of 80 Mbps data transfer is realized, and bandwidth up to 10 GHz is achieved at 300 K and gain of 1. British Leonardo Company has prepared SAM type HgCdTe APD detector with electron multiplication mechanism by metal organic vapor deposition（MOVPE）. The detectors were named Selex Avalanche Photodiode HgCdTe Infrared Array（SAPHIRA）, the device gain can reach 66@14.5 V, single photon detection efficiency is more than 90%. A 24 μm pitch 320×256 array SAPHIRA detectors were supplied to First Light Imaging Company in France to develop a C-RED ONE camera. The C-RED ONE camera was successfully applied to the Michigan Infrared Combiner（MIRC） for astronomical exploration in the United States, which reduced the system noise of MIRC by 10 to 30 times and greatly improved the signal-to-noise ratio of fringe detection. The research on HgCdTe APD detectors started relatively late in China. The main research institutions include Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Kunming Institute of Physics and North China Research Institute of Electro-Optics. Limited by chip preparation technology and circuit technology of HgCdTe APDs, the ability of photon counting has not been realized at present, but some progress has been made in the development of focal plane at home. The single element, 128×128 array and 320×256 array medium wave HgCdTe APD detectors with PIN structure are developed by Shanghai Institute of Technical Physics,Chinsese Academy of Sciences. The gain of the detectors can reach more than 1 000, the gain normalized dark current density is less than 1×10 -7 A/cm~2 within the gain of 100, and the excess noise factor is less than 1.5 within the gain of 400. At the gain of 133, the noise equivalent photon number is 12, and the short integration time fast imaging is demonstrated. Bandwidth of single element detector is up to 300-600 MHz. The single element and256×256 array medium wave HgCdTe APD device with PIN structure are developed in Kunming Institute of Physics. The gain of the single element detector can reach more than 1 000. When the bias voltage is less than 8.5V, the average gain normalized dark current of focal plane is 9.0×10 -14 -1.6×10 -13 A, and the excess noise factor F is between 1.0 and 1.5.Conclusions and Prospects In China, HgCdTe APD devices with planar PIN structure are mainly developed, and the technical path is basically the same as that of France. Therefore, our country can learn from the successful experience of CEA/LETI Laboratory and the business model of Lynred Company, and continue to promote research on HgCdTe APD detectors in order to reach the international advanced level as soon as possible, and realize single-photon detection and photon counting application.

Low noise is a key requirement of Readout Integrated Circuits (ROIC) in hyperspectral applications for its low radiation. Correlated Double Sampling (CDS) is commonly used to suppress noise. In this paper, CDS is improved by adjusting the time interval between the clamp and sample-and-hold (SH), which can filter low-frequency noise flexibly. An ROIC input stage integrated with low-noise capacitive trans-impedance amplifiers (CTIA) and CDS with adjustable interval (AICDS) is designed in 180 n m CMOS process. A timing generator is proposed to vary the interval regulation amount from 0 μs to 15 μs . The SPECTRE simulation indicates that, by decreasing this time interval, the noise electrons are significantly decreased from 48.72 e - to 22.15 e - , and SNR is enhanced by 5 dB (20 pA injection current). The design of AICDS can improve the noise performance of hyperspectral ROIC, thus can be widely used.

HgCdTe has been shown to be the first semiconductor exhibiting single-carrier multiplication in short-wavelength, medium-wavelength, long-wavelength avalanche photodiodes detectors for cut-off wavelengths from 1.3 µm to 11 µm corresponding to compositions xcd from 0.7 to 0.2, which has the remarkable characteristics of high gain, high bandwidth and almost no excess noise. These results have opened a new horizon in photon starved and high-speed applications, such as active imaging and free space optical communications. In this paper, we report the latest results at SITP of HgCdTe eFAPDs using LPE-grown absorption layers in the SW and MW wavelength bands. The gain of single element short-wavelength HgCdTe APD for 2.57 μm cut-off wavelength is about 100 at 25V reverse bias, and GNDCD is about 1.47×10- 7A/cm2 at gain of 100 at 130K. For MW HgCdTe APDs, increase the P region doping concentration will reduce the overall dark current density and eliminate sudden rise of dark current at large bias and high temperature, and lower Cd composition could be a trade-off way for GNDCD suppression. 50 μm pitch 128×128 array HgCdTe APDs for cut-off wavelengths 4.88 µm corresponding to compositions xcd 0.307 were fabricated, whose GNDCD is less than 1×10-7A/cm2 at 8V reverse bias, gain is over 1000 at 11V reverse bias. A 50 μm pitch 128×128 array HgCdTe APDs with xcd=0.29 was manufactured, whose gain reaches 1570 at 9.8V reverse bias, the average excess noise factor is 1.25 at average gain of 133, noise equivalent photon is about 12 at average gain of 113. By thinning the absorption region thickness, the response bandwidth of Hg0.79Cd0.31Te APD reaches 635MHz under 1V reverse bias. Moreover, the medium-wavelength focal plane of 320×256 array is demonstrated the imaging, and the low noise, high sensitivity and fast imaging characteristics of HgCdTe APDs under linear avalanche gain are verified.

HgCdTe avalanche photodiode (APD) is the frontier research on infrared focal plane technology. High-precision time stamp's readout circuit is the basis of the APD focal plane at 77 K, which directly affects APD infrared focal plane performance. Time-to-digital conversion circuit (TDC) is one of the methods to achieve high-precision time stamping. Based on the analysis of MOSFET device at low temperature, we design a vernier TDC circuit, which uses a synchronous counter to quantize an integer multiple of the periods to achieve a coarse count of 6 bits. We use the high-frequency clock multiplied by the on-chip phase-locked loop to quantify the part that is less than one clock cycle to achieve a fine-count of 6 bits output. The circuit adopts standard CMOS process tape out,and our circuit works at a master-frequency of 120 MHz. At 77 K, the circuit tests can distinguish the time resolution of 236. 280 ps. The DNL is within -0.54 similar to 0.71 LSB, and the INL is within -1.32 similar to 1.21 LSB.

High operating temperature infrared detector is one of the important development tendencies for the third-generation infrared focal plane. The interband cascade photodetectors take advantage of potential barrier structure and multistage absorption structure. Unidirectional transport of photogenerated carriers is achieved through relaxation and tunneling region which can reduce the generation-recombination current from the depletion region of the PN junction. The interband cascade detectors can effectively collect photo-generated carriers,and even the diffusion length is short utilizing the multiple and short absorption regions. So the detection performance can be improved at high operating temperature. In this paper,we present our recent research progress in the interband cascaded infrared optoelectronic devices,including high operation temperature infrared interband cascade detectors,high speed interband cascade detectors,and interband cascade light-emitting devices.

This paper mainly investigates the area-dependent gain and noise characteristics of mid-wavelength infrared (MWIR) Hg 0.7 Cd 0.3 Te planarelectron avalanche photodiodes (e-APDs) operated at 80 K. The 10- μ m-radius diode exhibits low dark current in the magnitude of 10 –13 A below −5.5 V, high gain up to 1270 at −10 V, and low excess noise factor between 1 and 1.2. The optimal performances are compromised by tunneling current, which should be further suppressed. Studies on variable-area diodes show that larger diodes have a reduced gain due to a smaller contribution from edge gain, as well as an increased 1/ f noise and corner frequency due to higher defect density. From the gain and noise perspectives, HgCdTe e-APDs with smaller junction areas are more suitable for focal plane array (FPA) applications.

Abstract Low noise is a significant performance requirement of Hyperspectral Shortwave Infrared Focal Plane Arrays Readout Circuit (ROIC) for its low radiation. And the current Correlated Double Sampling (CDS) technology for noise reduction needs to be further improved. The mechanism of extended reset time CDS, which has an impact on noise, is analyzed; By establishing the "first-order low-pass filter, delay-subtractor, sample-hold" model, the output noise power spectral density of image pixel ROIC as a function of CDS extended reset time is analyzed. To verify the analysis, a pixel integrated with low-noise Capacitive trans-impedance amplifiers (CTIA) and adjustable reset time CDS is designed. By extending the CDS reset time, the simulation result is consistent with the analysis. The number of noise electrons reaches 24.42e-, which is better than 50.11e-without CDS and 34.45e-without extending the reset time. The design of Reset Time Extended CDS can improve the noise performance of hyperspectral readout circuits, and can be widely used.

设计了一款基于线性模式下HgCdTe-APD的主被动双模式读出电路.被动模式下通过积分电容进行光信号的强度测量,主动模式下利用两段式TDC进行光子飞行时间(ToF)的标记.TDC采用面阵共享的数字计数器进行粗计数,像元内置时间幅度转换电路(TAC)进行精细测量,同时利用积分电容的切换修正时刻鉴别误差.焦平面阵列规模为32×32,工作温度为77 K,采用标准SMIC 0.18μmCMOS工艺进行电路设计及版图绘制.仿真验证结果显示,电路满阱容量约为7.5 Me-,在3.2 μs的动态范围ToF分辨率小于0.5 ns,DNL和INL分别在-0.15 LSB～0.15 LSB和-0.2 LSB～0.2 LSB范围内.读出电路帧频为4.5 kHz,功耗小于180 mW.

Infrared photon detection technology usually works in the passive sensing mode and contains the advantages of long acting-distance, good anti-interference, excellent penetration of smoke and haze, and all-day operation, which has been widely used in space remote sensing, military equipment, astronomical detection and other aspects. So far, the second-generation and the third-generation infrared photon detectors have been deployed widely. The high-end third-generation infrared photon detectors have been gradually promoted to practical application. The fourth generation and more forward-looking research including new concept, new technology, and new device has been proposed. This paper focuses on the research status of infrared technology at home and abroad, emphatically introducing the hotspots and development trends of infrared photon detectors. Firstly, the concept of SWaP(3) is introduced due to tactical ubiquity and strategic high performance. Secondly, the high-end third-generation infrared photon detectors with ultra-high spatial resolution, ultra-high energy resolution, ultra-high time resolution and ultra-high spectral resolution are reviewed. Technical characteristics and implementation methods of ultimate-performance infrared detectors are analyzed. Then, the fourth-generation infrared photon detector based on the artificial micro-structure is discussed. The realization approaches and technical challenges of multi-dimensional information fusion such as polarization, spectrum and phase are mainly introduced. Lastly, highly innovative trends of future detectors are discussed according to upgradation from on-chip digitization to on-chip intelligence.