排序方式: 共有57条查询结果,搜索用时 15 毫秒
11.
设计了一款长焦距大变倍比轴向变倍四视场中波红外光学系统.该光学系统由前固定组、变倍调焦组、中间补偿组、后固定组、反射镜一、反射镜二、中继组组成.光学系统采用光学补偿叠加机械补偿方式克服单一光学补偿或机械补偿变焦方式无法同时满足光学系统长焦距、大变倍比、光学系统小型化、光学系统宽温度范围(-40℃~70℃)温度补偿等问题,实现了兼具长焦距和大变倍比的轴向变倍四视场中波红外光学系统.设计结果表明该光学系统像质良好,满足热象仪整机使用要求. 相似文献
12.
双色中波红外图像的分割支持度变换融合 总被引:5,自引:1,他引:5
提出了基于形态学分割和支持度变换的双色中波红外图像的融合方法.通过腐蚀膨胀操作、加权叠加实现两幅细分波段图像的局部处理,消除了第一细分波段图像的太阳照射饱和区,然后利用支持度变换对图像进行融合,将两幅图像的细节信息综合起来,使图像更清晰.实验结果表明:同小波包变换融合方法相比,经本文算法融合后的图像有效消除了太阳照射造成的饱和区,太阳影响参数降低了60.05%,局部标准偏差和局部粗糙度分别增加了2.59%和3.39%,处理时间缩短了66.77%,证明了融合方法的有效性. 相似文献
13.
G. Brill S. Velicu P. Boieriu Y. Chen N. K. Dhar T. S. Lee Y. Selamet S. Sivananthan 《Journal of Electronic Materials》2001,30(6):717-722
The traditional substrate of choice for HgCdTe material growth has been lattice matched bulk CdZnTe material. However, as
larger array sizes are required for future devices, it is evident that current size limitations of bulk substrates will become
an issue and therefore large area Si substrates will become a requirement for HgCdTe growth in order to maintain the cost-efficiency
of future systems. As a result, traditional substrate mounting methods that use chemical compounds to adhere the substrate
to the substrate holder may pose significant technical challenges to the growth and fabrication of HgCdTe on large area Si
substrates. For these reasons, non-contact (indium-free) substrate mounting was used to grow mid-wave infrared (MWIR) HgCdTe
material on 3″ CdTe/Si substrates. In order to maintain a constant tepilayer temperature during HgCdTe nucleation, reflection
high-energy electron diffraction (RHEED) was implemented to develop a substrate temperature ramping profile for HgCdTe nucleation.
The layers were characterized ex-situ using Fourier transform infrared (FTIR) and etch pit density measurements to determine
structural characteristics. Dislocation densities typically measured in the 9 106 cm−2 to 1 107 cm−2 range and showed a strong correlation between ramping profile and Cd composition, indicating the uniqueness of the ramping
profiles. Hall and photoconductive decay measurements were used to characterize the electrical properties of the layers. Additionally,
both single element and 32 32 photovoltaic devices were fabricated from these layers. A RA value of 1.8 106-cm2 measured at −40 mV was obtained for MWIR material, which is comparable to HgCdTe grown on bulk CdZnTe substrates. 相似文献
14.
R. Haakenaasen H. Steen E. Selvig T. Lorentzen A. D. Van Rheenen L. Trosdahl-Iversen H. Syversen D. Hall N. Gordon 《Journal of Electronic Materials》2005,34(6):922-927
Imaging one-dimensional (1-D) and two-dimensional (2-D) arrays of mid-wavelength infrared (MWIR) and long-wavelength infrared
(LWIR) planar photodiodes were fabricated by ion milling of vacancy-doped molecular beam epitaxy CdxHg1−xTe layers. Sixty-four-element 1-D arrays of 26×26 μm2 or 26×56 μm2 diodes were processed. Zero-bias resistance-area values (R0A) at 77 K of 4×106 Θcm2 at cutoff wavelength λCO=4.5 μm were measured, as well as high quantum efficiencies. To avoid creating a leakage current during ball bonding to the
1-D array diodes, a ZnS layer was deposited on top of the CdTe passivation layer, as well as extra electroplated Au on the
bonding pads. The best measured noise equivalent temperature difference (NETD) on a LWIR array was 8 mK, with a median of
14 mK for the 42 operable diodes. The best measured NETD on a MWIR array was 18 mK. Two-D arrays showed reasonably good uniformity
of R0A and zero-bias current (I0) values. The first 64×64 element 2-D array of 16×16 μm2 MWIR diodes has been hybridized to read-out electronics and gave median NETD of 60 mK. 相似文献
15.
系统研究分析了红外光学系统中各个光学参数随温度变化的影响情况,根据红外硫系光学材料折射率温度系数较小的特点,并结合折反射结构良好的消热差特性,应用Code-v光学设计软件设计了一种折反式中波红外探测无热化成像系统,系统工作波段为3.7~4.8 m,焦距为109.7 mm,全视场角为6.4,F/#为2.0,满足100%冷光阑效率,采用锗、硫化锌和硫系玻璃AMTIR1三种红外材料,设计结果表明,该系统在低温-40 ℃、高温60 ℃时的成像质量和常温20 ℃的成像质量变化不大,取得了良好的成像性能,可匹配像元尺寸为30 m,像元数320256的凝视型焦平面阵列中波红外探测器。 相似文献
16.
该文报道了昆明物理研究所高工作温度中波红外碲镉汞焦平面探测器器件的研究情况。通过优化焦平面器件结构参数,采用As离子注入形成p-on-n平面结器件技术,在液相外延生长的高质量原位In掺杂的碲镉汞薄膜上制备了阵列规格为640×512@15μm的中波红外焦平面探测器。利用变温杜瓦测试了焦平面芯片在不同工作温度下的光谱响应、器件暗电流、噪声等效温差、有效像元率以及盲元分布等,测试结果表明器件具备180K以上工作温度的能力。 相似文献
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18.
Extrinsic p-type doping during molecular-beam epitaxy (MBE) growth represents an essential generic toolbox for advanced heterostructures
based on the HgCdTe material system: PiN diodes, mesa avalanche photodiodes (APD) or third-generation multispectral focal-plane
arrays. Today, arsenic appears to be the best candidate to fulfill this role and our group is actively working on its incorporation
during MBE growth, using an original radio frequency (RF) plasma source for arsenic. Such a cell is supposed to deliver a
monatomic As flux, and as expected we observed high As electrical activation rates after annealing short-wave (SW), mid-wave
(MW), and long-wave (LW) layers. At last, a couple of technological runs have been carried out in the MW range in order to
validate the approach on practical devices. p-on-n focal-plane arrays (FPA) have been fabricated using a mesa delineated technology on an As-on-In doped metallurgical heterojunction
layer grown on a lattice-matched CdZnTe layer (320 × 256, 30 μm pitch, 5 μm cutoff at 77 K). Observed diodes exhibit very interesting electro-optical characteristics: large shunt impedance, high quantum
efficiency, and no noticeable excess noise. The resulting focal-plane arrays were observed to be very uniform, leading to
high operabilities. Noise equivalent temperature difference (NETD) distributions are very similar to those observed with the
As ion-implanted p-on-n technology, fabricated in our laboratory as well. In our opinion, those excellent results demonstrate the feasibility of
our MBE in situ arsenic doping process. Good electrical activation rates and high-quality layers can be obtained. We believe that such an
approach allows precise control of the p-doping profile in the HgCdTe layer, which is necessary for advanced structure designs. 相似文献
19.
中波红外多光谱成像技术研究 总被引:1,自引:0,他引:1
多光谱成像技术结合成像和光谱测量技术,同时探测目标的光谱和几何特征,在目标识别和抑制背景杂波方面具有技术优势。研制了一套工作于中波红外波段的四通道多光谱成像系统。利用窄带滤光片和面阵探测器技术,构建了基于时序扫描的凝视成像型红外多光谱成像系统。根据红外探测器性能参数,对各个光谱通道的温度灵敏度进行了估算。在系统设计时通过合理地滤光片布局,尽量延长各个光谱通道的信号积分时间,以提高各个光谱通道温度灵敏度。利用研制的中波多光谱成像系统,对室外进行了成像,并对各个通道的成像结果进行了比较分析。 相似文献
20.