LED-based integrating sphere light sources (LED-ISLSs) in the size of typical microscope slides were developed to calibrate the radiance responsivity of optical imaging microscopes. Each LED-ISLS consists of a miniaturized integrating sphere with a diameter of 4 mm, an LED chip integrated on a printed circuit board, and a thin circular aperture with a diameter of 1 mm as the exit port. The non-uniformity of the radiant exitance of the LED-ISLSs was evaluated to be 0.8%. The normal radiance of the LED-ISLSs in the range of (5∼69) W m-2 sr-1 was measured with a standard uncertainty of 1.3% using two precision apertures and a standard silicon photodetector whose spectral responsivity is traceable to an absolute cryogenic radiometer. The LED-ISLSs were applied to calibrate the radiance responsivity of a home-built optical imaging microscope with a standard uncertainty of 2.6∼2.9%. The LED-ISLSs offer a practical way to calibrate the radiance responsivity of various optical imaging microscopes for results comparison and information exchange.

This article described the rotation angle system of the bidirectional reflectance distribution function (BRDF) measurement device. A high-precision multidimensional angle platform device is built. The rotation angle system uses two scanning rotational mechanical arms and a two-dimensional coaxial turntable mechanical structure, each rotational axis are driven by high-power motor and completed closed-loop control with high-precision encoder. Rotation of the motors can be automatically measured in accordance with point by the control software. The detecting arm can be rotated to measure any point in hemisphere space, the rotary range of light arm is ± 90 °, the rotary range of sample stage is 360 ° and the angular resolution is 0.01°. The rotation angle system meets the absolute positioning hemisphere space requirements of BRDF device. The experimental result shows that the rotation angle system met the high-precision positioning requirements for the BRDF absolute measurement.

The bidirectional reflectance distribution function (BRDF) diffuse plate as the standard of value transfer and carrier for BRDF, plays an important role in the study of radiometric calibration and scattering properties of. The space spectral characteristics of developed BRDF diffuse standard plate were measured by BRDF standard device. The standard BRDF values were given under more wavelengths and more geometric conditions in the visible to the infrared spectral bands, and the uncertainty is 1%. By comparison, the developed BRDF diffuse standard plate in visible and infrared bands reached the similar international standards plate level.

A large aperture uniform radiation source integrating sphere (URSIS) based on a 4m diameter internally illuminated integrating sphere with a 1.6m diameter exit port was designed and manufactured. This URSIS was used for pre-launch test and radiance calibration of large aperture imaging radiometers which fly aboard earth-borne remote satellites. Design criteria of the large aperture URSIS including sphere source radiance output, spatial radiance uniformity and radiance stability were presented. Integrating sphere internal lamp sources specifications and sphere coating selection were also concerned to suit the requirements of the multi-spectral-band imaging remote sensors. A new radiance calibration method of the URSIS based on Re-C blackbody was applied. The radiance calibration uncertainties varied from 2.8% to 3.5% with a coverage factor k=2 were achieved. The spectral radiance of the large aperture URSIS was characterized in the wavelength region from blue to near-infrared of spectrum. The spatial radiance uniformity of the large aperture URSIS was better than 99.0% and the stability was better than 0.4% over a period of 2 hours after an initial 30 minutes warm-up.

Although Ray tracing method is an effective aided design method in optical system, the uncertainty caused by this method is not very clearly. The relationship between the number of rays and uncertainty has been explored in this paper, while using the Monte Carlo algorithm in Ray tracing method. It shows that if the simulation relative deviation should be limited to 0.1%, at least 1000000 rays must be used.

To realize spectral diffuse reflectance scale in 0/d geometric condition at National Institute of Metrology in China (NIM), a facility based on a non-standard auxiliary integrating sphere method with special structure has been built up and a correction method for the influence on the thickness of PTFE (polytetrafluoroethylene) coating at the port of auxiliary integrating sphere is mainly discussed. The uncertainty of spectral diffuse reflectance in NIM is approximately 0.25% (k=2) in 380–800nm. This facility has been used to establish China diffuse reflectance scales in the VIS–NIR part of the spectrum. This system and correction method presented in this paper can be easily implemented on most commercial spectrophotometers with a lower cost.

To ensure measurement accuracy and reliable, and adapt to the development of the infrared transmittance calibration needs in China, this paper introduces the mid-infrared regular transmittance bilateral comparison organized by the China National Institute of Metrology. This comparison mainly focused on the wavelength band of 4000 cm-1-400cm-1(2.5μm -20μm). Technical protocol, facilities, measurement methods and conditions, and uncertainties from the participating laboratories have also been introduced.

We studied infrared normal spectral emissivity on quasi-periodic microstructured silicon, which was prepared by femtosecond laser irradiation in SF6 ambient gas, coated with 100 nm thick Au thin film. The observed emissivity is higher than any reported previously for a flat material with a thickness of less than 0.5 mm, at a temperature range of 200 °C to 400 °C. The emissivity over the measured wavelength region increases with temperature and the spike height. These results show the potential to be used as a flat blackbody source or for applications in infrared thermal sensor, detector, and stealth military technology.

Regarding to the mistakes that optoelectronic devices such as CCD focal plane arrays devices are often placed on the exit port plane of integrating sphere source to perform calibration, the output irradiance uniformity of integrating sphere source is analyzed, the basis which rational using the integrating sphere source to calibrate the optoelectronic devices is obtained. Two theoretical output irradiance uniformity models based on numerical analysis method and Monte Carlo method are developed respectively. The models consider two fundamental situations of integrating sphere sources, namely (1) ideal lambertian source and (2) non-ideal lambertian source. The distribution regularity of irradiance uniformity was generalized by contrast of the theoretical data obtained by the models and the measured data obtained by two different actual integrating sphere sources. The results show that when (1) the diameter of optoelectronic device is less than half diameter of the sphere exit port, and (2)the ratio of the distance from device to exit port and the exit port diameter are between 3 and 5, a 99% better output irradiance uniformity can be obtained. The results provide a practical guide to ensure the accuracy of the calibration exercise of optoelectronic devices.

设计了一种新颖的双回转子孔径扫描装置,得到了可以覆盖大口径光学系统全口径的子孔径扫描光斑,从而满足了大口径光学系统光谱透射特性的测试需求.结合双回转扫描装置的结构参数误差,基于齐次坐标变换矩阵原理,建立了双回转扫描装置的数学模型,提出了一套分析子孔径扫描精度的方法,并且在设计双回转子孔径扫描装置中实现了应用.分析结果表明,当双回转子孔径扫描装置的回转半径ηr≤400 mm时,子孔径扫描精度△ηr为-0.007～0.028 mm.提出的子孔径扫描误差估计方法、建立的扫描运动坐标转换模型和得到的误差数据结果可作为类似回转扫描机构的设计参考,也为基于双回转子孔径扫描方法的大口径光学系统光谱透射特性测试的深入研究提供了理论依据和数据基础.

High-precision measurement for fluorescence quantum efficiency of solid materials has been a very cumbersome and complex process. In recent years, though many scholars have done a lot of studies, the relative and simplified measurement are mainly been emphasised on, and it is very difficult to obtain the accurate measurement uncertainty. Refering to NRC, on the basis of the little appropriate transformation on commercial instruments, this paper introduces the absolute quantum efficiency measurement for solid materials, based on double monochromator method. Currently, the measuring wavelength covers 250-800nm, the uncertainty of quantum efficiency is about 5%(k=2).

The infrared normal spectral emissivity of microstructured silicon prepared by femtosecond laser was measured for the middle infrared waveband at temperature range 200 to 400°C. Compared to that of flat silicon, emissivity was enhanced over the entire wavelength range. For a sample with different spike height, the max emissivity at a temperature of 300°C emissivity nearly reaches to 0.99 . Although the average emissivity is not very higher, it can be used stably at more wide temperature ranges. These results show the potential for microstructured silicon to be used as a flat blackbody source or silicon-based devices.

Based on Fourier infrared spectrometer, the mid-infrared normal spectral emissivity measurement device with high accuracy was developed in Spectrophotometry Laboratory, National Institute of Metrology, China. It was composed of Fourier infrared spectrometer, black body, heater and the auxiliary optical components. It can work at 100 to 450°C with heating function and can work at up to 1100°C only for self-heating materials or systems. The measurement wavelength range covers the whole middle infrared light 2.5-25um, and the measurement uncertainty is better than 2%(k=2) at any measurement temperature point for self-heating materials or systems.

In the progress of wavenumber traceability using polystyrene films, different peak-seeking algorithms are discussed in this paper. Conclusion shows that in commonly used methods, spline method, center of gravity method and the second derivative method, spline method is better than the others with simple algorithm and good agreement. It is strongly recommended to use in practical for calibrating FTIR spectrometer.

To meet the pre-launch radiometric calibration requirements of large field of view (FOV) imaging remote sensors, a large-area integrating sphere uniform radiation source (ISURS) based on a 1600mm diameter internally illuminated integrating sphere with a 620mm diameter exit port was designed. The software TracePro based on ray-tracing method was applied to computer modeling of the ISURS. It is shown that the angle of internal radiation source from the center of the sphere is an important factor affecting the spatial radiance uniformity at exit port. Taking this factor into account, the model established is able to obtain the important characteristics of the sphere source. With the characteristics obtained, the ISURS was manufactured and its optical parameters were measured. The measurement result of the spatial radiance uniformity of the large-area ISURS was 99.19%. There is a discrepancy of 0.12% between measured and simulated results. It is demonstrated that the method used and the model established can increase the efficiency of designing large-area sphere radiation source.

Low BRDF value is widespread used in many critical domains such as space and military fairs. These values below 0.1 Sr-1. So the Absolute realization of these value is the most critical issue in the absolute measurement of BRDF. To develop the Absolute value realization theory of BRDF, defining an arithmetic operators of BRDF, achieving an absolute measurement Eq. of BRDF based on radiance. This is a new theory method to solve the realization problem of low BRDF value. This theory method is realized on a self-designed common double orientation structure in space. By designing an adding structure to extend the range of the measurement system and a control and processing software, Absolute realization of low BRDF value is achieved. A material of low BRDF value is measured in this measurement system and the spectral BRDF value are showed within different angles allover the space. All these values are below 0.4 Sr-1. This process is a representative procedure about the measurement of low BRDF value. A corresponding uncertainty analysis of this measurement data is given depend on the new theory of absolute realization and the performance of the measurement system. The relative expand uncertainty of the measurement data is 0.078. This uncertainty analysis is suitable for all measurements using the new theory of absolute realization and the corresponding measurement system.

For measuring large-aperture optical system transmittance, a novel sub-aperture scanning machine with double-rotating arms (SSMDA) was designed to obtain sub-aperture beam spot. Optical system full-aperture transmittance measurements can be achieved by applying sub-aperture beam spot scanning technology. The mathematical model of the SSMDA based on a homogeneous coordinate transformation matrix is established to develop a detailed methodology for analyzing the beam spot scanning errors. The error analysis methodology considers two fundamental sources of scanning errors, namely (1) the length systematic errors and (2) the rotational systematic errors. As the systematic errors of the parameters are given beforehand, computational results of scanning errors are between -0.007 similar to 0.028mm while scanning radius is not lager than 400.000mm. The results offer theoretical and data basis to the research on transmission characteristics of large optical system.

The opto-electronic conversion function (OECF) is defined as relationship between input luminance and digital output levels for an opto-electronic digital image capture system. It is a fundamental parameter to evaluate the performance of digital still-picture camera. An experiment device was set up to measure OECFs by using test charts with twelve neutral patches stepped in different visual density increments and a integrating sphere uniform illuminator. To determine the camera OECFs, images of the test charts were captured under controlled conditions for computer to calculate. For each trial, the mean digital output level shall be determined from a 64 by 64 pixel area located at the same relative position in each image. Several digital still-picture cameras were selected as test samples and their OECFs were different under a larger range of illumination. Besides, the dynamic range, incremental gain and SNR also have been calculated using the OECF test charts images data.

During the process of developing product, AO directly affects assembly efficiency and assembly quality for mechanical product. Usually, new mechanical product is developed according to the knowledge and experience. So it is very important how to utilize the knowledge and experience to plan the AO. This paper presents a planning approach based on CBR for AO of mechanical product. Firstly, a method based on hierarchy model represents AO cases. And we store the AO cases into the AO Case Library to accumulate the knowledge and experience of assembly process. Secondly, the Euclidean distance is applied to calculate the similar characteristic between the component of AO of Query (AOQ) and the component of the AO cases in the Library. When some distances are less than the value, the corresponding AO cases are selected to the next calculation. Thirdly, the Manhattan distance is applied to calculate the similar characteristic between AOQ and the selected AO cases. When the distance is minimal, the optimal AO case is obtained. The approach is applied successfully to plan AO for a part of aircraft's wing.

The high absorption characteristics, the complex mechanism and the great potential application in detectors of micro-structural material aroused extensive attention. In order to understand the impact of the micro-structure, the optical simulation method based on Monte Carlo is used for reflection characteristics of micro-structural material with the cell of pyramid construction. In this simulation, the body material is made of gold, which can avoid the effect of tranmittance, with a number of 400 cells. The bottom square of each structure is 50×50 µm, and the height of cells is adjustable. Then the relationship between the height and reflectance can be built up. However, a very complex relationship between the reflectance and the input parameters, including refractive index, extinction coefficient and the structure of the material is showed from simulation result. Generally, the reflectance decreases while the height increases.