Development of Sub-Femtosecond Pulsed Laser Processing System

• Main Authors: Chin-HungWang, 王智弘
• Other Authors: Shean-Jen Chen
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/48743112266253578179

碩士 === 國立成功大學 === 工程科學系碩博士班 === 101 === In this thesis, we want to develop a sub-femtosecond pulsed laser machining system integrated with prism pair and acousto-optic modulator (AOM) for 3D imaging and processing of bio-tissue. Because of conventional laser machining systems (even at nanosecond pulse) have very serious thermal effect. There are many disadvantages such as melting residues, micro-cracks, and poor fineness etc. They can be significantly improved via using femtosecond laser, but generally speaking, the pulse width of femtosecond laser is about 100 fs, there is still has thermal effect in such pulse width level. Dispersion effect will be very severe issue when machining pulse width is below 100 fs. The SF-11 prism pair was utilized to compensate overall optical system’s second order dispersion. The major compensation components are AOM and objective. After compensating, the system pulse width is 45 fs, and the AOM was utilized to become laser switch and laser pulse selector for precision control the dose of laser intensity. We get the two-photon image from different sizes of fluorescent beads and second harmonic generation image from chicken tendon. Finally, we also use different pulse width on bio-tissue processing. Improving the image spatial resolution, processing efficiency, and reducing thermal effect have been successfully accomplished.