Femtosecond laser micro-machining

• Main Author: Wee, Jonas Chee Yong
• Other Authors: Wonkeun Chang
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Engineering; Physics
• Online Access: https://hdl.handle.net/10356/176918
• Institution: Nanyang Technological University

Femtosecond laser micro-machining is a precise and advanced laser technique. It can emit ultrashort laser pulse in the femtosecond range (10-15 seconds) with intense high peak power, allowing precise material removal. This technique minimizes thermal damage to the surrounding material while maintaining structural integrity, offering extreme precision and accuracy. This property makes the Femtosecond laser micro-machining suitable to be used on a wide range of materials opening possibilities for various applications. Femtosecond laser micro-machining is a cutting-edge technology that brought significant advancement to the micro-fabrication of optical fibers. The optical fiber is a glass filament which is as thin as a human hair therefore requiring very precise fabrication. Although there are different microfabrication techniques such as direct laser ablation and arc discharge, these techniques have limitations in terms of precision and thermal damage to the surrounding material. However, the introduction of femtosecond laser micro-machining highly precise and controlled micro-structuring with minimized thermal damage to the surrounding material has enabled the creation of intricate and complex micro-structures on optical fibers, expanding the capabilities in various domains. With the help of femtosecond laser micro-machining, one key application of optical fiber achieved is the gas sensing fiber. This project serves to explore the factors of femtosecond laser micro-machining affecting the quality of the micro-machined structure and find the best balance between the factors for creating smooth and optimised access for gas filling of the hollow-core optical fiber.