Spectral response is one of the important technological parameters of the detector, along with the development of the ultraviolet detector technology, accurate measurement of UV detector spectral responsivity is becoming more and more important. This paper analyzes the ultraviolet focal plane array relative spectral responsivity measurement principle, using the substitution method of measuring ultraviolet focal plane array detector relative spectral responsivity, and established a calibration device for relative spectral response of UV focal plane array. The relative spectral response of UV focal plane array device was obtained,can be seen from the curves, UV focal plane array device from 250 nm to 290 nm spectral response range, the peak response near 270 nm, Show that the array sun-blind characteristic of a device. The uncertainty of analysis results showed that UV focal plane array device relative spectral response measurement uncertainty of calibration device is about 3.6%, can meet the demand of high precision measurement.
Terahertz metrology is becoming more and more important along with the fast development of terahertz technology. This paper reviews the research works of the groups from the physikalisch-technische bundesanstalt (PTB), National institute of standards and technology (NIST), National physical laboratory (NPL), National institute of metrology (NIM) and some other research institutes. The contents mainly focus on the metrology of parameters of power, frequency, spectrum and pulse. At the end of the paper, the prospect of terahertz metrology is predicted.
Modulation transfer function (MTF) is one of the most important parameters of infrared focal plane array (IRFPA). A double-knife edge scanning method is proposed for MTF measurement of IRFPA. In this method, a double-knife edge was used as a target, and the IRFPA under test was positioned in the focal plane of the imaging optical system by a 3-axis translation stage. With an IRFPA data acquisition system, the image of the double-knife edge was restored. By scanning in the direction orthogonal to the double-knife edge image, edge spread function (ESF) curve of each pixel swept across the knife-edge image was obtained. MTF could be calculated from the subsequent fitting, differential and Fourier transformation procedures. With double-knife edge scanning, two ESF curves of double-knife edge were obtained simultaneously, and symmetry of the two ESF curves could be used to evaluate the verticality between photosensitive surface of IRFPA and optical axis of the double-knife edge imaging system. In addition, this method can be used to judge the existing of interference from outside such as vibration, stray light and electrical noise. A measurement facility for IRFPA’s MTF based on double-knife edge scanning method was also established in this study. The facility is composed of double-knife edge imaging optical system, 3-axis translation stage and data acquisition system, et al. As the kernel of the facility, the double-knife edge imaging optical system mainly comprises two symmetrical parabolic mirrors coating with reflective material, and the magnification of the optical system is 1 with an operation wavelength range of (1∼14) μm.