All Fiber High-speed Delay Scanning Method And Experiment Research That Can Be Used In OCT System

The speed of imaging is an important sign in optical coherence tomography (OCT). It depends on the scanning-speed of the fiber-optic delay line. The dissertation proposed the fiber-optic delay line with fiber optic winding the PZT. It has a quick scanning-speed, the low exhaust of inserting. When PZT is driving by high-speed and high voltage, it will show capacitance characteristics. It caused too much power waste of the drive circuit. This intensified the designing difficulties of the high-power drive circuit; on the other hand because of PZT fever seriously, it resulted in static fiber optical path and linear birefringence change so that the performance of a fiber-optic delay line degradation. So, the research on the drive method of high-speed, the much delay of the all-fiber delay line, is known as a one of the key technologies.This dissertation focused on the structural design, production, and the driver and other issues of all fiber-optic delay line, carried out the following research work:Firstly this dissertation designed mathematical model on fiber-optic delay line. It discussed the various factors of influencing optical fiber delay and designed the structure of all fiber-optic delay line.The dissertation researched drive circuit based on Boost circuit and LC resonant circuit. It designed the structure of the circuit to drive fiber delay line by using the pulse width modulation (PWM) with the LC resonance. It raised the supply voltage of the PZT by Boost circuit and LC resonant technology and offset the shortage of output voltage caused by using a simple LC resonant technology, resulting temperature changes of piezoelectric. PWM-LC resonant technology is useful to improve scanning frequency and output voltage of fiber delay line.Lastly, it used to measure the characteristics of all fiber-optic delay line. The experimental results showed that the largest amount of delay of the fiber-optic delay line can achieve2.50mm with the frequency of 200Hz and the voltage of 450V, and the experimental results were analyzed.