Omni-Directionally and All-Optically Controllable Dye-Doped Cholesteric Liquid Crystal Fiber Laser

Abstract

This thesis successfully develops and investigates all-optically and omni-directionally controllable dye-doped cholesteric liquid crystal (DDCLC) infiltrating photonic crystal fiber (PCF) and coaxial capillary (CC) lasers In the process of fabrication the laser dye-doped CLC (LDDCLC) and azo-dye-doped CLC (ADDCLC) selectively infiltrate into the core and cladding of the PCF sample that is the internal capillary and the gap between the internal and external capillaries of the CC sample respectively The LDDCLC in the core of the PCF or the internal capillary of the CC self-organizes as a radially symmetric planar structure consequently enabling the LDDCLC to function as an optically active Bragg-onion cavity By contrast the ADDCLC in the cladding of the PCF or the gap of the CC self-organizes as a focal conic structure As a result the ADDCLC functions as an all-optically and omni-directionally controllable light shutter The lasing output from the LDDCLC-filled region can be all-optically controlled to emit omni-directionally or semi-directionally or off-emit in the isothermal phase transition between scattering focal conic state and transparent isotropic state through the UV beam-induced trans-cis and blue beam-induced cis-trans back isomerizations of the azo LCs in the ADDCLC-filled region The potential of all-optically controllable PCF or CC in bio-image photo-therapy wearable devices and transparent displays is significant

Date of Award	2014 Aug 28
Original language	English
Supervisor	Chia-Rong Lee (Supervisor)