一些辐射学和光度学的测量是以高精度测量精密光阑面积为基础的，因此高精度测量孔径光阑的面积有着至关重要的意义。目前高精度测量孔径光阑面积主要有以下两类方法：接触法与非接触法，几何法与有效面积法。本文首先对各种方法进行简单介绍，并对非接触法、几何法和有效面积法进行重点阐述。最后通过对比不同方法的测量精度、实现难易程度以及测量设备成本情况，得出结论：几何法和有效面积法是非常有前景的。然而要进一步提高孔径光阑面积的测量精度，稳定的激光光源、精准的移动平台是必不可少的。

Some radiometric and photometric measurements need high accuracy knowledge of the area of the aperture. So the accurate knowledge of the area of the limiting aperture is very important. There are two types of methods to measure the aperture areas. Type-one contains contract method, and no-contract method, and type-two contains geometrical method and effective area method. In this paper we first describe all the methods briefly, then emphatically explain the no-contract method, geometrical method and effective area method. Finally, a comparison of measurement accuracy, degree of difficulty in measurement, and equipment cost among different methods, indicates that the geometric method and the effective area method are very promising. In order to improve the uncertainty of the measurement, more stable laser and accurate translation stage are needed.

以同一品种同一批次玉米单倍体和多倍体个体种子为研究对象,基于近红外光谱定性分析技术,分析研究了用漫透射光谱测量方式采集光谱时,不同光照强度和光阑孔径得到的光谱曲线质量以及对玉米单倍体种子鉴别结果的影响.光谱数据经过预处理后,采用PLS+ OLDA特征提取算法,应用SVM建立玉米单倍体鉴别模型.分别统计多种不同实验条件所测数据建立的鉴别模型的正确识别率.结果表明,光阑孔径的大小影响光谱曲线信噪比,越接近玉米籽粒大小的孔径获得的光谱曲线越平滑;光照强度影响光谱曲线有效性,光照越强,波形峰谷差值越大,识别率越高.选择较高的光源强度和适合种子大小的光阑,可以得到高质量的光谱曲线,以此建立的玉米单倍体鉴别模型,识别率达到了100％.

Aiming at the same batches of the same variety corn seeds, this paper studied the influence factors about the spectral curve quality and the recognition rate of maize haploid identification based on NIR qualitative analysis technology. The factors were studied from the two aspects which were the light intensity and diaphragm aperture with the diffuse transmission spectrum measurement way. Partial least squares-discriminant analysis (PLS-OLDA) was used to compress the pretreated spectral data, and then the identification models were built based on Support Vector Machine (SVM). The measured data were recorded under different experimental conditions and the recognition correct rates were calculated. The results showed that the signal to noise ratio of light spectral curve is affected by the amount of light through the diaphragm, and the closer to the seed size the aperture diameter of the diaphragm is, the smoother spectrum would be got. The intensity of light source directly in

基于同轴三反射光学系统基本原理,将孔径光阑和视场适当偏心,设计了一个灵巧型多光谱离轴三反光学系统,系统焦距1 200mm,并对设计结果进行了像质评价。实验结果表明:系统在可见波段(0.486μm~0.656μm)80lp/mm空间频率下MTF0.5,中波波段(3μm~5μm)15lp/mm空间频率下MTF0.35,全波段范围内最大RMS为2.096μm。系统中面型采用二次非球面,且整个系统仅有孔径光阑偏心,3个反射镜位置均无偏心和倾斜,降低了加工成本及装调难度。

Based on the theory of coaxial three-mirror reflective optical system and by decenter-ing the aperture stop and the field of view ,a compact and multispectral off-axial three-mirror reflective optical system with 1 200 mm focal length was designed .Furthermore ,the image quality was evaluated .The design results prove that the modulation transfer function(MTF) is above 0 .5 at 80 lp/mm for 0 .486 μm ~0 .656 μm ,above 0 .35 at 17 lp/mm for 3 μm ~5 μm and the root-mean-square (RMS) radius is less than 2 .096 μm in full waveband .Moreover , three mirrors w hich use cone surfaces instead of high order aspherical surfaces are not decen-tered or tilted and only the aperture stop is decentered ,so it is easy to fabricate and assemble .

大相对孔径变焦系统在像差补偿自由度较少的光学补偿式变焦系统中,通常需采用较多的镜片才能完成像差校正,导致系统体积和质量不甚理想。通过合理分配变焦参数,优化变焦系统结构,并进行非球面与衍射面复合叠加设计,完成了一个仅含8片透镜的光学补偿式变焦系统。相对孔径1∶1.8,采用320像素×240像素制冷焦平面探测器,工作波段3μm~5μm,变倍比为5×,实现了30mm/60mm/90mm/150mm四档变焦,冷光阑效率100%。折叠光路后,体积约为210mm×100mm×85mm,结构紧凑,以较少的镜片数辅以机械结构的光学补偿变焦方式有效减轻了整机质量。

Optical system with a large relative aperture has a larger entrance pupil than its coun-terparts w hen their focal lengths are equal ,so more energy collected and further distance detec-ted .But due to its large aperture ,the aberrations increase ,w hich requires more lenses to cor-rect and consequently cause application restrictions by volume and weight .To tackle this is-sue ,zoom parameters were calculated and optimized reasonably ,moreover by adopting com-pounded aspheric and diffractive surfaces ,a reimaging zoom mid-wave infrade (MWIR) system with only 8 lenses was designed .The F number is 1 .8 and the spectrum is 3μm~5μm .For a 320 × 240 pixels detector with cooled focal plane array (FPA) ,the magnification is 5× ,and the four fields of view (FOVs) are 30 mm/60 mm/90 mm/150 m .The optical aperture stop mat-ches the detector''s and the cold stop efficiency is equal to 100% .Two reflective mirrors are ap-plied to fold the optical path ,giving a compact volume of aro