Journals >Opto-Electronic Advances
Contents
2019
Volume: 2 Issue 10
3 Article(s)
Export citation format
Contents
Opto-Electronic Advances 2019, Vol.2, No.10 Contents
N/A
Opto-Electronic Advances
- Publication Date: Jan. 07, 2020
- Vol. 2, Issue 10, 1 (2019)
Review
A review on control methodologies of disturbance rejections in optical telescope
Tao Tang, Shuaixu Niu, Jiaguang Ma, Bo Qi, Ge Ren, and Yongmei Huang
Structural vibrations in Tip-Tilt modes usually affect the closed-loop performance of astronomically optical telescopes. In this paper, the state of art control methods—proportional integral (PI) control, linear quadratic Gaussian (LQG) control, disturbance feed forward (DFF) control, and disturbance observer control (Structural vibrations in Tip-Tilt modes usually affect the closed-loop performance of astronomically optical telescopes. In this paper, the state of art control methods—proportional integral (PI) control, linear quadratic Gaussian (LQG) control, disturbance feed forward (DFF) control, and disturbance observer control (DOBC) of Tip-Tilt mirror to reject vibrations are first reviewed, and then compared systematically and comprehensively. Some mathematical transformations allow PI, LQG, DFF, and DOBC to be described in a uniform framework of sensitivity function that expresses their advantages and disadvantages. In essence, feed forward control based-inverse model is the main idea of current techniques, which is dependent on accuracies of models in terms of Tip-Tilt mirror and vibrations. DOBC can relax dependences on accuracy model, and therefore this survey concentrates on concise tutorials of this method with clear descriptions of their features in the control area of disturbance rejections. Its applications in various conditions are reviewed with emphasis on the effectiveness. Finally, the open problems, challenges and research prospects of DOBC of Tip-Tilt mirror are discussed..
Opto-Electronic Advances
- Publication Date: Jan. 07, 2020
- Vol. 2, Issue 10, 190011 (2019)
Recent improvement of silicon absorption in opto‐electric devices
Takashi Yatsui
Silicon dominates the contemporary electronic industry. However, being an indirect band-gap material, it is a poor absorber of light, which decreases the efficiency of Si-based photodetectors and photovoltaic devices. This review highlights recent studies performed towards improving the optical absorption of Si. A summSilicon dominates the contemporary electronic industry. However, being an indirect band-gap material, it is a poor absorber of light, which decreases the efficiency of Si-based photodetectors and photovoltaic devices. This review highlights recent studies performed towards improving the optical absorption of Si. A summary of recent theoretical approaches based on the first principle calculation has been provided. It is followed by an overview of recent experimental approaches including scattering, plasmon, hot electron, and near-field effects. The article concludes with a perspective on the future research direction of Si-based photodetectors and photovoltaic devices..
Opto-Electronic Advances
- Publication Date: Jan. 07, 2020
- Vol. 2, Issue 10, 190023 (2019)
© Copyright 2018-2021 | Chinese Laser Press. All Rights Reserved 沪ICP备15018463号-20