In order to reflect the output characteristics of real seeker under disturbance rejection rate, a concept and test method of seeker transfer function based on disturbance rejection rate parasitic loop were proposed. Through the establishment of seeker disturbance rejection rate model, the transfer function of disturbance rejection rate with effect of different disturbances was derived. The stability region of disturbance rejection rate parasitic loop was analyzed, and the regulation of parasitic loop instability frequency was obtained. The transfer function model of seeker with parasitic loop was established, and the frequency characteristics and time domain characteristics of the real seeker model were simulated and analyzed. Finally, the hardware-in-loop simulation test method of seeker transfer function based on parasitic loop was proposed. Through the hardware in the loop simulation test, the real seeker model is obtained, so as to improve the accuracy of seeker modeling.

Due to the limitations of system volume, the large field of view(FOV) detection method of laser fuze can not meet the requirements of system miniaturization. Aiming at the requirements of full detection in sagittal direction and narrow-FOV detection in meridian direction, a method of emission optical system with large FOV and miniaturization for laser fuze was proposed. The tunnel junction LD laser as a light source, a reasonable mode of FOV configuration was choiced, and an optical system with three-quadrant and sector-shaped emission was designed, which was characterized by small size, large FOV, reasonable structure, simple installation. The volume of single emission optical system was 8 mm×8.2 mm×15 mm, the single FOV in sagittal direction was more than 120°. The large FOV detection requirements of portable laser fuze whose diameter was Φ70 mm for air defense missile was satisfied, and the problem of miniaturization for full FOV laser fuze was solved.

A multiple-columns-shared-parallel pipelined successive approximation register (SAR) analog-to-digital converters (ADC) was presented for high speed CMOS image sensors (CIS) application. As the pixels in 8 columns shared one pipeline-SAR ADC, the layout was no longer restricted to double pixel pitches, and can be implemented within 16 pixel pitches. Asynchronous logic was implemented to improve the conversion speed of multiple-columns-shared-parallel pipeline-SAR ADC. A half-gain multiplying digital-to-analog converter (MDAC) was used for the residue amplification to relax the requirements for the operational amplifier (opamp), and correlated level shift technique was also used for more precise amplification. The 12-bit resolution was divided by 6-bit coarse and 7-bit fine SAR sub-ADC with 1-bit stage redundancy calibration between coarse and fine steps. Input full scale voltage was 1 V. The ADC was designed in 0.18 μm 1P4M CIS process, and occupied 0.204 mm2 for 8 columns. The simulated results of the ADC showed a SNDR of 72.6 dB with a 229.7 kHz input and 71.7 dB with a 4.16 MHz input at 8.33 Msps. It dissipated 4.95 mW at 1.8 V supply and the FoM was 172.5 fJ/conversion-step. Because the pixel pitch is only 7.5 μm and the process has only 4 metals, this proposed 12-bit multiple-columns-shared-parallel pipeline-SAR ADC is quite suitable for the high speed CIS.

There are increased application requirements of Terahertz wave low frequency radiometers in Earth atmosphere and molecular detection. Based on the equivalent circuit model and their resonant characteristics′ simulation design of the microwave electrical split ring resonators(eSRR), novel microstructured photoconductive antennas(PCAs) were proposed by combining the microwave resonant structure with the traditional stripline dipole PCA. The new PCAs were with high frequency adjustment sensitivity and obvious resonance characteristics. The novel PCAs with different dimensions were fabricated and experimentally compared with a conventional stripline dipole PCA. The terahertz radiation spectrum of the two types PCAs are significantly different: the novel PCAs have dual resonant peaks and narrowband resonating characteristics owing to the dual-frequency resonant characteristics of the microstructured eSSRs, and the 3 dB relative bandwidth is about 50%; while the conventional PCA has only a single peak with broad spectrum radiations, whose the 3 dB relative bandwidth is 93.07%. The simulation and test results of the new PCAs agree well. It is demonstrated that adjusting the resonant ring′s arm length of the new PCAs can obtain a relatively larger peak frequency shift. Thus the theoretical model and the simulation results are all verified.

An electrically controlled terahertz wave switch was designed and proposed based on double layer graphene structure. The switch was made up of prism - graphene - SiO2 - graphene - InSb. The terahertz wave was incident from the left side of the prism at a specific angle, and the terahertz wave detector was fixed on the right side of the prism. By adjusting the external voltage bias, the refractive index of the graphene layers was changed in order to control the reflectance to achieve the purpose of terahertz switching. COMSOL software was used to simulate the double-layer graphene electronic switch.Terahertz wave with frequency of 1 THz was incident at 35.42° from the top of the prism in experiment. When there was no external electric field, the reflectivity of terahertz wave was 2.63%, which was defined as the "off" state of the terahertz wave switch. When the applied electric field was applied, the dielectric constant of graphene changed, and the reflectivity of terahertz wave changed to 93.01%. The structure of prism was close to total reflection, which was defined as the "open" state of terahertz wave switch. The simulation results show that the device has good performance in controlling the intensity of the terahertz wave. Extinction ratio of the switch was 15.5 dB.

A visual tracking method via object detection based on deep learning was proposed. In consideration of the advantages of deep learning in feature representation, deep model SSD(Single Shot Multibox Detector) was used as the candidate object extractor in the tracking model. Simultaneously, the color histogram feature and HOG(Histogram of Oriented Gradient) feature were combined to select the tracking object. In the process of tracking, multi-scale object searching map, which was applied to implement the object detection in different scales, was built to improve the detection performance of deep learning model. In the experiment of eight respective tracking video sequences in the baseline dataset, compared with six typical tracking methods, the proposed method has better performance in tracking effect, and has better robustness in the tracking challenging factors, such as deformation, scale variation, rotation variation, illumination variation, and background clutters.

In order to improve abilities of human vision for situation perceiving and the recognition rate of the targets in gray scale image, a color transfer method of luminance remapping with multi-parameters was proposed to colorize the gray scale image. First, the RGB color spaces of the gray scale target image and the color reference image were converted to the YCbCr color space, in which the luminance value and color were separated. Then, the parameters which depended on the number of columns and luminance values of the color reference image and the gray scale target image were introduced. The luminance values of the color reference image were calculated to ensure the color reference image and the gray scale target image have the same range of luminance values. At last, according to the correlation of the neighborhood, each pixel of gray scale target image was matched with the pixel of the color reference image. The matched result was converted inversely to the RGB color space, which can represent a variety of colors. The occurrence of color misinformation is decreased in color transfer method of luminance remapping with multi-parameters. The accuracy degree of the color transfer is increased. At the same time, the running time of the program is reduced.

Aiming at the requirement of automatic target recognition, a method of laser and infrared fusion target recognition is proposed. Firstly, wavelet moment and projection contour feature are extracted respectively from laser and infrared datas respectively. Secondly, two kinds of single source features are combined, and then the features are reduced. Considering the combination of multiple reductions will produce complementary information, three different views of the reduction algorithm are adopted to construct the diversity combination classifier. Then the fusion recognition method of laser and infrared fusion is presented. Finally, the effectiveness of the proposed method is verified by the experiment of laser and infrared simulation data.

In order to inspect accurately the condition of early wheat powdery mildew, and also to provide technical support for spraying pesticides, in this study hyperspectral imagery data of different disease severity for wheat leaves were collected at the early infection stage. Firstly, the leaf area and lesion area were segmented by image features, and then the disease severity was calculated quantitatively. Secondly, the Relief-F algorithm was introduced to select the most sensitive band and band difference, on the basis, the powdery mildew disease index(PMDI) was calculated. Moreover, the correlations between disease index(DI) and 11 vegetation indices(Including PMDI index) were analyzed, it was found that the PMDI index has the highest coefficient of determination(R2=0.839 9) and the lowest root-mean-square error(RMSE) which is 4.522 0. It was better than that of other disease vegetation indices, in which the result of normalized difference vegetation index(NDVI) was the highest, the determination coefficient is 0.777 1 and the RMSE equals 5.336 4. Finally, the support vector regression(SVR) models of PMDI and NDVI indexes were established, respectively, to further compare the retrieval performance for disease severity of early wheat powdery mildew. The result shows that the prediction model of PMDI index is better than NDVI index, the R2 is 0.886 3 with RMSE=3.553 2. It can be concluded that the developed method can effectively realize nondestructive diagnosis of early wheat powdery mildew, and provide important help for the spraying and disease control.

A optical distributed vibration sensing(DVS) scheme based on the space difference of Rayleigh backscattering was presented for perimeter security. In this scheme Rayleigh backscattered light with phase changes induced by vibration signal along the sensing fiber was split and fed into an imbalanced Michelson interferometer. The space difference of Rayleigh backscattering was realized. The DVS system realized the phase demodulation of the Rayleigh backscattered light to improve the sensitivity of the system. The distributed vibration sensing system based on space difference of Rayleigh backscattering can restore the walking route, the velocity of the intruder and the distance of the simulative digger, and obtain the demodulated signal SNR of 15 dB and detection distance of 35 m.

A novel method of subcarrier evolution was proposed to analyze the nonlinearity of an intensity-modulation direct-detection(IMDD) orthogonal frequency division multiplexing(OFDM) passive optical networks(PON). The nonlinearity was mainly caused by the subcarrier-to-subcarrier intermixing interference(SSII) and the chirp from the modulation. The fiber disperssion results in that the optical subcarrier can not keep the best initial phase matching condition which exacerbates the signal distortion. A new modified Volterra digital filter was also proposed to cancel the signal distortion of the IMDD OFDM PON. The modified Volterra digital filter included not only the same samples but also the different samples. The corresponding experiments had been carried out to verify the effectiveness of the proposed signal distortion cancelation method. The proposed modified Volterra filter could bring about 3 dB power benefits than the previous work to meet the forward error correction(FEC) limit of 10-3. The transmission penalty over 25 km at the FEC limit of 10-3 was lower than 0.5 dB. Finally, the system can reach a data rate of 24.5 Gbps, and the spectrum efficiency can achieve up to 7 bits·s-1·Hz-1. These experimental results prove that the modified Volterra filter can effectively compensate the linear and nonlinear distortion and therefore it can recover the signal at optical network unit (ONU).

Temperature drift is one of the main factors that affect the accuracy of fiber optic gyroscope (FOG), and its modeling and compensation are effective methods to eliminate and reduce the drift. The key factors that affect the temperature drift of FOG were analyzed. Meanwhile, the test experiment of FOG temperature drift was carried out. Then, the support vector machine which had better generalization ability than the neural network was used to regress and model the temperature drift of FOG, and the radial basis kernel function was adopted as the kernel function of support vector machine which had better data set adaptability. In order to improve the modeling accuracy of support vector machine, the artificial fish swarm algorithm was used to optimize the penalty factor C of support vector machine and the factor of kernel function. Finally, the proposed compensation method was verified by the actual temperature drift data of FOG, which showed that the remaining error of FOG compensated by the proposed method was reduced by 4-5 orders of magnitude than that compensated by the linear regression method.

In order to improve the adjusting accuracy of space telescope secondary mirror Stewart mechanism, the precision calibration is necessary. For the 6-PSS Stewart adjusting mechanism, first of all, the parameter calibration model was obtained by the kinematics and the least square method. Secondly, the usually cuckoo search based on simplex(SMCS) method was modified by use of VSA and limitation bounds algorithm to improve the global accuracy of optimization problem. The better calculation ability compared to SMCS was verified by the simulation results. Finally, to ensure the validity of the whole travel distance, a test data sampling process included six elements of position and orientation was planned. Experimental results show that the displacement error at the sampling point is reduced from the maximum 19.97 μm to 9.68 μm, and the angle error is reduced by a maximum of 123.84″ to 8.86″. Similar results are also shown with good accuracy at the non-sampling points, the proposed method based on the aforementioned model can effectively improve position accuracy of the secondary mirror adjusting mechanism, and the compensation results is efficient for the whole travel distance.

For the long-wave infrared camera which has a temperature sensitivity less than 10 mK, it is an important work of testing its noise equivalent temperature difference(NETD) with high accuracy. Firstly, the "black body direct testing method" was chosen based on the principle of shortening the standard radiation transfer link and reducing the error terms after comparing different testing methods; Secondly, based on the theoretical noise model of the long-wave infrared camera, the testing noise data was analyzed at different temperatures, the noise correction method was proposed for reducing the testing error caused by the instability of environment. Finally, the uncertainty of testing results was analyzed based on the NETD calculation formula and analysis theory of uncertainty. The result shows that the testing device and methods are satisfied for the testing requirement of ultra-high sensitive long-wave infrared camera, the testing uncertainty is 7.7%.

Probability of detection(POD) is one of the most important indexes to evaluate the reliability of detection in eddy current pulsed thermography(ECPT). Generally, the probability of detection is defined as the probability that the defect with fixed size is detected under the given detection conditions. Firstly, a series of metal plates with different lengths of fatigue cracks were introduced to obtain the thermal response signals through the design of orthogonal experiment. Secondly, a linear regression model was established to describe the relationship between thermal response signals and crack lengths, and the maximum likelihood estimation(MLE) method was employed to achieve the specific parameters of the crack POD model. Finally, the resulting confidence interval of POD was presented based on Wald method, and the curves of POD were drawn. The research results can provide a quantitative evaluation method for detection reliability in ECPT.

The accurate calculation of IR emissivity is the basis of modeling and analyzing the ship turbulent trailing wake in IR. Based on Cox-Munk probability distribution function(PDF) of slopes model, and corresponding to bi-directional reflectance distribution(BRDF) function of sea surface, a method for calculating IR emissivity of ship turbulent trailing wake in typical ocean environment was formulated. According to calculation, the emissivity distribution of typical ship turbulent trailing wake in 8-9 μm long-IR band for both small zenith angle of airborne detection and big zenith angle of shipborne detection were studied. The results show that the difference of emissivity between turbulent trailing wake and sea background is increased along with the detecting zenith angle. What′s more, the radiance of turbulent trailing wake of typical ship is calculated in cloudy autumn shipborne detection condition, which is compared with the sea trial data. The results show that in typical ocean condition, the radiance of turbulent trailing wake is lower than sea background, presenting the characteristic of "cold trailing wake".

In order to study the temperature-dependent photoelectric characteristics of the extended wavelength In0.8Ga0.2As PIN infrared detectors, based on planer process with sealed-ampoule diffusion method, front-illuminated 256×1 linear planar InGaAs detector arrays were fabricated on NIN-InAs0.6P0.4/In0.8Ga0.2As/ InAs0.6P0.4 buf./InP materials by metal organic chemical vapor deposition (MOCVD). And the I-V characteristics, spectral response and detectivity of the detector at different temperatures were analyzed. The results indicate that the forward dark current is dominated by the generation-recombination current and gradually becomes the diffusion current with temperature dropping. Diffusion current and generation-recombination current were the main resource of reverse current of the detector between 260 K and 300 K. The tunneling current predominated at temperature below 180 K. The cutoff wavelength and peak wavelength were 2.57 μm and 2.09 μm at room temperature. The peak detectivity, peak responsivity and quantum efficiency was 7.25×108 cm·Hz1/2/W, 0.95 A/W and 56.9% respectively. Furthermore, the average peak detectivity of the detector arrays reached a peak value of 1.11×1011 cm·Hz1/2/W and the response nonuniformity was about 5.28% at 153 K.

The existed infrared intensity and polarization image fusion algorithm could not dynamically adjust fusion algorithm according to the change of image difference characteristics,which results in that the partial differences feature fusion effect was not ideal or even failure.According to thought of mimicry bionics and learning from Mimicry Octopus′s multi-mimicry process, a fusion method of combination fusion of multi-types mimic variable of infrared intensity and polarization images was proposed. Firstly, Mimicry Ooctopus′s multi-mimicry process,the reason of multi-mimicry were analyzed. Secondly, the correspondence between multi-mimicry process and image fusion process was found, and multiple types variables of the image fusion process were determined.Finally, a reversible variable composition relation for image fusion was established and image fusion was carried out that used the combined relation. The experimental results showed that the information entropy, standard deviation, edge intensity, average gradient and sharpness of the obtained fusion image were obviously improved 1.16%, 7.25%, 3.00%, 0.31%, 10.18% in average. The establishment of this method could make the fusion algorithm within the variable selection and combination according to the original image difference characteristics of the dynamic adjustment, so as to obtain a targeted fusion algorithm.

Single junction GaAs solar cells were irradiated by 808 nm and 10.6 μm continuous wave lasers respectively. The results show that, as long as under the same laser coupling intensity, the damage modes of solar cells under two different irradiation conditions are similar. As the laser coupling intensity increases, the maximum output-power of solar cells shows a ′stair-step′ decline. Damage processes was further investigated through analysis of temperature rising rate, peak temperature, duration of high temperature and variance, as well as energy disperse spectroscopy and scanning electron microscope measurements. It is found that the high temperature during irradiation process leads to the dissociation of GaAs and the oxidation of the electrodes, which further results in performance degradation of single junction solar cells.

The scattering characteristics of aerosol backscattering laser echo in aerosol has important influence on the waveform characteristics. In order to obtain the scattering characteristics of aerosol backscattering laser echo, we took fog as the research subject, and simulated the multiple scattering process of backscattering signal in fog by using the model of laser propagation in fog, and calculated the scattering times and propagation time under different fog mass concentrations and fog distances, and analyzed the range of scattering times, the features of same- scattering times echo, and the influence of fog mass concentration and fog distance on the scattering times. The results of this paper can provide an important support for the analysis of the characteristics of aerosol backscattering laser echo.

A tunable wavelength phase shifting interferometry based on current modulation was proposed to achieve on-site measurement of the interferometers with integrated configuration. The wavelength was modulated by changing the current injected into the laser diode (LD) to achieve temporal phase shifting interferometry. The traditional random phase shifting interference model was optimized, and phase was retrieved by iterative algorithm using least-squares techniques to solve linear regression, which suppressed the interference of unequal interval phase shifting arising from the limit of controlling precision of the current modulation and nonlinearity of LD, and synchronized phase of each sampling point caused by environmental vibration. Experimentally, the proposed method is applied to an on-site Fizeau interferometer to test an optical flat, and the measurement results are compared with Zygo GPI XP/D interferometer, where the error of their peak-to-valley value is 9.91 nm and the error of root-mean-square value is 5.22 nm, which meets the requirement of online measurement and achieves quantitative measurement. The proposed method can be applied to other laser interferometers.

In laser bending forming, the warping deformation influences the forming accuracy. Based on ANSYS software and electron microprobe, process of the warping deformation for stainless steel-carbon steel composite plate including interfaces bended by pulsed laser was simulated using a multi-layered finite element model (FEM) in single-pass scanning. By simulating temperature field, stress field, residual stress distribution and the free end deformation of the composite plate, the process and the reason of warping deformation were analyzed. The results show that during laser scanning, the uneven rate of the highest temperature on the scanning line is 18.33%, which is influenced by initial temperature and edge effect. After 0.2 s heat conduction and heat loss, heat accumulation phenomenon appears in middle area, which leads to warping deformation caused by increased thermal stress. Simulation results of the residual stress from scanning line to free end show that, warping force within the region and constraint counterforce at the edges of the region are produced, warping deformation matches both the magnitude and direction of the simulation result. The max error of warping line between the experiment and simulation is 3.90% and the error of chordal height is 3.33%, which provids the calculation basis for better bending angle control of the composite plate.

Current terrain classification methods using waveforms of a laser altimeter are mainly based on machine learning, which is an empirical model. Starting from the theoretical model of the laser waveform, by deriving the analytic model of laser waveforms of sea surface and sea-ice surface, the sum of the amplitude differences between the sea waveform and sea-ice waveform was calculated according to one by one sampling point based on the temporal-distance weighting; and the sea or sea-ice waveform was classified by the calculated difference value. The terrain types corresponding to GLAS laser footprints in the north sea-ice area of Greenland were obtained by analyzing the point clouds captured by an airborne LiDAR, and in this area, the GLAS measurement waveforms were used to validate based on the classification method proposed in the paper. The results indicate that after eliminating the effect of saturated waveforms, the overall accuracy OA is better than 95% and the Kappa coefficient is approximately 0.89, which achieves a high classification accuracy. The new method extends the terrain type classification from taking the machine learning as basis to taking the semi-theory analytic model as basis for a laser altimeter, which can be an important reference to the terrain type classification based on laser waveform successively.

A high-power high-efficiency narrow-bandwidth thulium-doped fiber laser (TDFL) with output wavelength 1 915 nm was studied in this work. The thulium-doped fiber laser was based on system of master oscillator power amplifier (MOPA). The laser diode with about 40 W output power and 793 nm wavelength was used to pump double cladding large-mode-area (LMA) thulium-doped fiber with 25 μm core diameter, the narrow-bandwidth continuous wave(CW) seed laser with wavelength 1 915 nm and maximum power 12.1 W was obtained. When the 793 nm pump power was 142.9 W, after the 8 W seed laser going through the thulium-doped fiber amplifier, the output laser had average power of 90 W, central wavelength of 1 915.051 nm, and the 3 dB spectrum bandwidth was 94 pm, with slope efficiency of 60%, and optical-to-optical conversion efficiency of 63%. The stability of output laser of this system behaves well in the 40 min operation checking time.

Aiming at the problem of wide pulse pedestal and lower pulse energy of passively mode-locked fiber laser based on Semiconductor Saturable Absorber Mirror(SESAM), a double SESAM passively mode-locked ultrashort pulse fiber laser based on linear cavity structure was designed. Firstly, through increasing the number of SESAM, the optical pulse would pass through the SESAM repeatedly in one oscillating period in the cavity, the absorption of the absorber was improved to the pulse front and back edge, the Q mode-locked effect due to larger pump power was suppressed, contributed to pulse compression and raised the single pulse energy, the effect of the SESAM lower modulation depth on the pulse width and single pulse energy was eliminated. Secondly, the introduction of positive dispersion in the system could reduce the nonlinear effect caused by the peak power, and further improving the pulse energy. Finally, compared with the single SESAM mode locking under the same modulation depth and saturation flux, the output pulse width of the double SESAM mode-locked fiber laser shorted 35.2%, from 693 fs to 449 fs, and the single pulse energy raised 45%, from 2.92 nJ to 5.31 nJ.

A passively continuous-wave(CW) mode-locked Tm:YAP laser with a semiconductor saturable-absorber mirror was reported by using laser-diode as pump source. According to the ABCD matrix theory, the astigmatism and the stability in the cavity of the laser were theoretically analyzed. Stable continuous-wave mode-locked ps-pulses were achieved. The average output power of 0.73 W was obtained with the absorbed pump power of 7.96 W and the corresponding slope efficiency was 15.6%. The pulse duration was measured to be 1.7 ps with a repetition rate of 88.7 MHz at the central wavelength of 1 982.4 nm, and the corresponding slope efficiency was 15.6%. The results show that the Tm:YAP crystal has good thermal mechanical properties, which is very favorable for generating ultrashort pulses at around 2 μm.

In order to meet the requirements of infrared gas detection for high performance laser driving power supply, the PID control algorithm was adopted, a high stability DFB laser driving power supply was designed and manufactured. Its hardware mainly included signal generation module, voltage-controlling current source module, circuit protection module. The system had the function of output current protection. In the signal generation module, the sine wave was generated by DDS and then square waves was generated through a comparator. At the same time, DA conversion technique was adopted to realize the output of DC wave, triangular wave and sawtooth wave. Meanwhile, in respect of control scheme, the current high stability was effectively ensured by the use of PID control algorithm and veep negative feedback. With this driver, the driving test was performed on a DFB laser with a center wavelength at 1 563.09 nm. The results show that the driver has the function of the output waveform type, amplitude and frequency can be changed by digital control, the current amplitude ranges from 0 to 1 A and the frequency range is from 1 Hz to 1 MHz. The frequency resolution is 1 Hz. The linearity of the system is 99.93% and the long term output current stability reached 0.019 7%.

2 μm InGaSb/AlGaAsSb single quantum well(SQW) laser with low threshold current density of ~131 A/cm2 and its ideality factor n was presented. The ideality factors n of the central p-n junction and the n-GaSb/metal junction sum up to be the total ideality factor n of the laser. The total ideality factor n decreases from 4.0 to 3.3 when the temperature was increased from 20 to 80 ℃. The results are in good agreement with the applied theoretical model as well as the ideality factor n of the individual GaSb-based junctions(p-n junction, GaSb/metal junction etc.).

Antimonide materials are the ideal system for the semiconductor photoelectric materials and devices of 2-4 μm due to its narrow bandgap. In recent years, great progress has been made in the research of antimonide high-power semiconductor lasers at home and abroad, and the room temperature operation of high-power single-tube and array lasers has been achieved. However, due to the incompatibility of antimonide materials with common fabrication technique of semiconductor single-mode lasers, only a few research institutes and companies have mastered the preparation of antimonide single-mode lasers. In this paper, the basic principle of the laterally coupled distributed feedback laser was introduced and the key technologies of the laser were briefly analyzed. The design scheme and preparation technology of the antimony single mode laser were also reviewed and summarized.

2 μm GaSb-based high power semiconductor laser has a promising prospect in many fields, such as gas detection, medical cosmetology and laser processing. The structure development of 2 μm GaSb-based high power semiconductor laser based on power improvement was reviewed and discussed, the current research situation at home and abroad was introduced, and the principal technical issues in power and efficiency improvement were discussed. Two new structures introduced in traditional lasers in this field were introduced in detail, and their technical advantages were analyzed. It also pointed out the current 2 μm GaSb-based high power semiconductor lasers were facing bottlenecks, and their development trends were discussed.

The core imaging spectrometer developed by Nanjing Center of China Geological Survey consisted of a visible near infrared (VNIR) imaging spectrometer, a short wave infrared (SWIR) imaging spectrometer and a guide railway on which the core plate was mounted. The control accuracy of the uniform-speed moving guide railway and the different spatial resolutions and fields of view (FOV) of the VNIR imaging spectrometer and the SWIR imaging spectrometer caused geometric distortions on the core data. So the data obtained cannot be directly used for subsequent applications. In the face of these potential problems, on the basis of analysis error mechanism, geometric correction method based on the triangle calibration and joint image registration method of pixel and sub-pixel level were proposed. By setting triangle calibration target on one side of a core plate, geometric stretch and compression distortion was detected and corrected. By introducing scale invariant feature transform and extensible phase correlation, registration accuracy was improved. Experimental results using core hyperspectral data produced by Nanjing Center of China Geological Survey show that this improved geometric correction method can achieve a stretch and compression correction accuracy of 0.28 pixel and registration accuracy better than 0.1 pixel.

A technique of space-coded multiplexing speckle was proposed to simultaneously obtain multiple objects′ information by a single-pixel detector. Space-coded multiplexing speckles were employed for objects illumination. The mixed light reflected from the objects was detected by a single-pixel detector. An iterative reconstruction method was used to restore the fused image. The spatial coding information was used to decode multiple objects′ information. Next, clear images of the different information were recovered by compressed sensing (CS) algorithm. Multi-space, multi-spectral and multi-polarization information were simultaneously obtained through the proposed technique, respectively. The results clearly demonstrate that the proposed method is effective. This method can effectively reduce the amount of detected data and improve the imaging efficiency.