KEYWORDS: Precision measurement, Position sensing equipment, Signal to noise ratio, Signal processing, Interference (communication), Sensors, Detection and tracking algorithms, Signal filtering, Distortion, Neural networks
The spot position detection technology based on the four-quadrant detector plays an important role in fields such as laser semi-active guidance, space laser communication, medicine, and precision measurement. The paper systematically summarizes the research progress of high-precision spot position detection technology based on the sum-and-difference algorithm model. First, the improved algorithm models under four conditions are discussed, namely the circular spot and uniform distribution, the circular spot and Gaussian distribution, the elliptical spot and uniform distribution, and the elliptical spot and Gaussian distribution. Further optimization algorithms based on these four models are also introduced. On this basis, although the detection accuracy has been significantly improved, there are still other factors that affect measurement accuracy in practical applications, such as inconsistent quadrant responsivity, noise, atmospheric turbulence, etc. These factors and their influencing trends or correction methods are classified and summarized. With the development of hardware processing capabilities, more new signal processing methods are being used to improve detection accuracy or precision, such as the digital lock-in amplifier method, the neural network method, the Kalman filtering method, etc. Some of these signal processing methods and their positive effects are introduced. Finally, prospects for future development are discussed.
The simulations of quasi one-dimensional (1D) and quasi three-dimensional (3D) device process and optoelectronic performance were conducted on silicon APD array pixels using Silvaco, realizing micro region analysis of the electric field distribution, avalanche gain, and photoelectric response characteristics of the APD photosensitive region. The multiplication coefficients corresponding to different positions of APD pixel were obtained and compared with the ideal 1D device structure. The results show that the multiplication factor of the center region of APD pixel is significantly higher than that of the edge of the photosensitive region. The simulation of microlens to converge the incident light to the center of the photosensitive region confirmed the increasement of APD avalanche multiplication current, i.e. the quasi 3D structural APD response is increased from 13.6 A/W to 54.8 A/W, and the effective fill factor is increased from 20.9% to 84.2%. Thus, the utilization rate of incident light is effectively improved.
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.