Actively mode-locked fiber laser with feedbcak control system

• Main Author: Xue, Jin.
• Other Authors: Sheel Aditya
• Format: Final Year Project
• Language: English
• Published: 2012
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Optics, optoelectronics, photonics
• Online Access: http://hdl.handle.net/10356/49625
• Institution: Nanyang Technological University

In this project, a frequency stabilized pulsed laser system is proposed. Two main parts of the system – pulsed laser source and feedback control loop are both investigated analytically for their underlying mechanisms. All the components adopted in the experimental setup are described in detail for their functions and specifications. The laser source adopted is an actively mode-locked Erbium-doped fiber ring laser with 0.3 nm optical bandwidth, 6 MHz fundamental frequency and 2 GHz modulation frequency. The feedback control loop is based on a piezoelectric tube (PZT) whose size varies with different DC bias strengths. By tightly winding a segment of fiber laser cavity on the PZT, an error signal can be generated by using the output of the laser source to dynamically change the laser cavity length itself and thus the repetition frequency of the output pulse. To verify the function of the proposed system, an experimental demonstration is also conducted in this project, in which a laser pulse train with greatly enhanced stability and significantly reduced noise is observed.