Auto-focusing Technique Based On Operator Fusion For Coupling Optical-taper With CCD

The technique of optical fiber-taper coupled with CCD is widely used in the imaging system of space payload, low light level night vision system, television tracking of missile system and remote sensing imaging system. In the coupling process, how to estimate the coupling efficiency real-timely is a difficulty. In order to solve the problem, some important studies are practiced in this dissertation. A novel auto-focusing method based on operator fusion is introduced to the system for coupling optical fiber-taper with CCD and a numbers of outcomes are achieved in this dissertation.Firstly, focus measures and focus algorithms such as frequency spectrums function, gradient functions and entropy functions are analyzed respectively in detail. By comparing the advantage of the focus algorithms, a novel image-evaluation function, which based on the operator fusion technique, is also proposed. By experiments, it is proved that reliability of the arithmetic is enhanced, and a higher accuracy is achieved.Secondly, an auto-focusing method based on Operator Fusion is introduced to the system for coupling optical fiber-taper with CCD. In the developed system for coupling optical-taper with CCD, the stepping-motor is droved and in the same time the images are sampled. By using a novel image-evaluation function, which based on the operator fusion technique, the image serial is calculated, compared and the best of the image serial is acquired. Ultimately, the coordinate of the best image is fed back to control the stepping-motor to obtain the best coupling position. By this way, the system noise is declined and the SNR (Signal Noise Ratio) of the coupling device are improved.By the coupling experiments, it is proved that the system noise is declined and the SNR of the coupling device is improved. The problem how to obtain the best efficiency of coupling during the coupling process, is successfully resolved in this method.