Development of Optical Coherence Tomography Laser Source

• Main Authors: Min Sheng Chang, 張閔盛
• Other Authors: W. P. Lin
• Format: Others
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/24107901129017765666

碩士 === 長庚大學 === 電機工程學系 === 103 === In this thesis, we did a research of creating good quality swept source. we use a mode-locked fiber laser (MLFL) with pulse-width of 370fs and peak power of 10kW as a light source. The light source is pumped into a 110-m-long highly nonlinear fiber (HNLF) with nonlinear coefficient of 11.7 w-1km-1, and a compensated 60-km-long dispersion compensation fiber (DCF) with dispersion of -1020ps/nm is used to generate swept source. The center wavelength of swept source is at 1558nm, and is measured in time-domain with pulse-width of 6.6ns and frequency of 70MHz. In order to confirm the swept rate of the swept source, interference method is used to get swept rate which is 47MHz. The swept range can be calculated which is 7.45nm. To improve the swept range, we use single mode fiber (SMF) to replace dispersion compensation fiber. With measured of different length of single mode fiber, variety data can be got which indicates that when using 4.4-km-long single mode fiber, swept range is 32.62nm and swept rate is 13.37nm/ns. This swept light source is the most suitable for optical coherence tomography (OCT).