With the rapid development of national defense, aerospace and other fields, the demand for high precision and high quality photoelectric products is increasing day by day, and these photoelectric products are gradually developing toward miniaturization. If the optical elements use a free-form, the imaging quality of the optical imaging system can be greatly improved, and the illumination uniformity of the optical illumination system and the transmission efficiency of the information transmission system can also be remarkably improved. With free-form optics becoming the leading representative technology of advanced optical engineering, optical metrology technologies for free-form optics has become the hotspot research of current science-technology development. In this paper, the development of optical metrology technologies, the present situation and the advantages and disadvantages of various metrology technologies are described in detail, which will be of guiding significance for future research on optical metrology technologies for free-form optics.
With the continuous development of space optical technology, the aperture of optical system is becoming larger and larger, and the aperture of optical elements is required to be larger. When the traditional optical inspection means are used to detect optical elements such as large aperture optical plane, large aperture convex spherical surface and convex aspheric surface, optical reference mirror or optical auxiliary element with larger aperture than the detection element is usually needed, such as compensator and computer generated hologram (CGH) etc. However, these large-diameter optical reference mirrors and auxiliary components are not only difficult to process, but also have long processing cycle and high production cost. At the same time, some processing errors and assembly errors will be introduced. In order to solve these difficulties, this paper will introduce a modified phase retrieval (PR), which is phase-diversity phase retrieval (PDPR) algorithm can improve the PR accuracy of the unknown image, but also can provide a strong basis for the online testing of the future larger aperture astronomical telescope optical system and solve the difficulties in the detection of optical systems in space optical telescopes. Therefore, this study has important practical significance and application value in the online testing of the space optical telescope optical system.
Road surface meteorological conditions are very important for traffic safety. According to the statistics, the ratio of traffic accidents that occur on icy, wet and dry road surface is about 4.2:1.6:1. A remote road surface meteorological condition sensor based on multi-wavelength light was developed in this paper which could identify the road surface condition including dry, wet, icy and snow, that may be vital for preventing traffic accidents. By using multi-wavelength optical remote sensing technology and near infrared light source, the diffuse reflectance spectrum of road surface can be detected. The four road surface states of dry, wet, ice and snow can be measured with non-contact method, and the thickness of pavement water film can also be measured. Such road sensors were used on G50 highway in Chongqing, China. Experiment results show that the system could meet the requirements well.
Large-aperture telescope with its high spatial resolution and high light gathering capability plays an important role in military, astronomy and other fields. The demand for large aperture imaging telescope is increasingly urgent, the aperture becomes larger and larger, and the splicing main mirror has become the development trend of large-aperture telescope which brings great challenges to the optical processing and testing. This paper proposes phase-diversity phase retrieval technology which can provide a strong basis for the online testing of the future larger diameter astronomical telescope optical system and solve the difficulties in the detection of optical systems in large-aperture telescopes. Therefore, this study has important practical significance and application value in the online testing of the large-aperture telescope optical system.
Measuring optical wave-fronts precisely is a difficult task because detectors directly sense intensity, not phase. The most common method of measuring the phase uses an interferometer that creates an intensity distribution from which the phase of the field can be determined more easily. In order to overcome the wave-front distortion caused by atmosphere turbulence and optical system aberration, the system of wave-front solutions based on the focal plane image information can be used in the optical system in-line detection. The realizations of phase solver technology mainly include phase diversity and phase retrieval. So, this paper mainly explains phase diversity and phase retrieval.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.