Owing to the ability of generating designated spectrums as special requirements, spectrum-controllable light source has attracted huge interesting in several fields, e.g. medical science, industrial detection, defense-related testing. In principle, optical performance of a spectrum-controllable light source can be predicted by some transfer functions of the corresponding system, e.g. modulation transfer function (MTF). Unfortunately, the aforementioned research work is still lacking at present although it is meaningful for the optical design and evaluation of this new kind of light sources. Hence, a MTF model for a modified version of our previously-proposed spectrum-controllable light source system based on a Digital Micromirror Device (DMD) and an Offner dispersion configuration with a convex grating is deduced as an example. Related preliminary analyses have been present in this paper as well.
Spectrum-controllable light sources are able to generate desired spectrums as specific requirements, which have attracted huge interesting in many fields, e.g. life science, machine vision, defense-related science and technology. A controllable light source in the range from 0.38 to 0.78 μm, which is based on a Digital Micromirror Device (DMD) and an Offner dispersion configuration with a convex grating, is proposed in this paper. Due to its fast speed, high fidelity and simplicity with all spherical elements, the Offner relay is chosen as the dispersion structure compared with other existing spectroscopic configurations. The DMD located on the spectral image plane of the dispersion configuration is used to choose spectral channels according to the desired spectral radiance distribution through modulating micromirrors. The optical system of the proposed digitally spectrum-controllable light source is designed and further simulated by Zemax.
Due to its excellent performance, free-form large astronomical mirrors are playing an important role in astronomical optical telescope. Compared with traditional simple astronomical mirrors, the manufacture and the testing for such kind of mirrors are more complex and difficult since the influence of surface characteristics. In recent years, a gradientsensing technique based on fringe reflection (FR) is becoming a powerful tool for free-form large astronomical mirror testing owing to its advantages of high accuracy, fast speed, large dynamic range, etc. As an important part of FR, shape integration based on gradient information straightforwardly affects the accuracy of surface reconstruction. To overcome some problems of the existing shape integration methods, e.g. high-frequency information easily missing in Fourier integral method, a high sampling rate requirement in directly linear least-squares integral method based on Southwell’s model, etc., an improved shape-integral algorithm with hybrid iteration for surface reconstruction under sparse sampling considering the features of free-form large astronomical mirrors is proposed in this paper. Simulation results demonstrate the effectiveness of the proposed method.
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.