Optical deposition of carbon nano-particles for functional photonics devices

• Main Author: Tan, Wai Kiat.
• Other Authors: Asst Prof Chow Kin Kee
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Optics, optoelectronics, photonics
• Online Access: http://hdl.handle.net/10356/54318
• Institution: Nanyang Technological University

Fibre laser that generates ultra-short pulse at high repetition rate has many uses in various applications. To generate such pulses, mode-locking is employed, which is a technique that allows the generation of ultra-short pulses usually in the order of picoseconds or femtoseconds and at a repetition rate higher than or equal to megahertz range. Passive mode-locked laser is usually preferred as the laser structure is much simple and do not require any external input. One of the crucial components in passive mode-locked laser is the saturable absorber. Recently in the optic research community, 2 carbon-based nanomaterials, carbon nanotube and graphene, have been found and they possess distinct properties of saturable absorber and are found better than the current semiconductor saturable absorber. Many researches have been done to develop methods on how to incorporate the nanomaterials into fibre laser. A novel method called optical deposition with optical reflectometry has been proposed and shown that it is the easiest and most efficient method to deposit the nanomaterials onto the fibre core. In this project, deposition of both nanomaterials on fibre end and FC/UPC fibre end using optical deposition with optical reflectometry has been successful. The deposition has been investigated and a conclusion is drawn that the deposition is not predictable as it depends on various factors during the deposition process. Both nanomaterials have demonstrated saturable absorber capabilities that help to generate ultra-short pulses at a very high repetition rate.