Wide-Band Spatially Tunable Photonic Bandgap and Lasing Emission using Polymer Stabilized Blue Phase

Abstract

This thesis successfully develops a gradient-pitched polymer-stabilized blue phase (PSBP) photonic bandgap (PBG) device with a wide-band spatial tunability The device is fabricated based on the reverse diffusion of two injected BP-monomer mixtures with a low and a high chiral concentration Experimental results show that the formed PSBP PBG device can be spatially tuned from the blue (481 9 nm) to the red (646 9 nm) regions within 14 mm at room temperature The entire spectral range of tunability is as wide as 165 nm This thesis also studies the tuning characters of the polymer-stabilized dye-doped BP (PSDDBP) laser Experimental results present that the tuning spectral range of the laser is around 58 nm which is about 82 nm narrower than that of the corresponding PBG The discrepancy between the tuning features of the two devices is attributable to several factors: the dye’s reabsorption of fluorescence photons at short wavelength regions the weak dye’s fluorescence emission at long wavelength regions and the significant fragmentation of the frustrated BP with large lattices The temperature sensitivity of the lasing wavelength for the PSDDBP laser is linear and approximately 0 26 nm/°C which result is attributed to the constant and negative dn/dT The two devices have a great potential for use in applications of photonic devices and advanced displays because of their advantages such as wide-band tunability fast tuning speed high stability and reliability no issue of hysteresis and no need of external controlling sources

Date of Award	2014 Aug 25
Original language	English
Supervisor	Chia-Rong Lee (Supervisor)