The University of St Andrews

Research@StAndrews:FullText >
Physics & Astronomy (School of) >
Physics & Astronomy >
Physics & Astronomy Theses >

Please use this identifier to cite or link to this item:
This item has been viewed 22 times in the last year. View Statistics

Files in This Item:

File Description SizeFormat
The full text of this document is not available.pdfplaceholder2.61 kBAdobe PDFView/Open
Title: Organic semiconductor lasers : compact hybrid light sources and development of applications
Authors: Yang, Ying
Supervisors: Samuel, Ifor D. W.
Turnbull, Graham
Keywords: Organic electronics
Hybrid optoelectronics
Distributed feedback
Issue Date: Jun-2010
Abstract: This thesis describes a number of studies on organic semiconductors as laser gain media with the aim of simplifying the excitation scheme and exploring potential applications. A hybrid device taking the advantage of high power inorganic light emitting diodes (LEDs) and low threshold organic distributed feedback lasers is demonstrated to realize a LED pumped organic laser. When the drive current is higher than 152 A, a sharp peak is clearly observed in the laser output spectrum, implying the LED successfully pumps the polymer laser above threshold. This is the first time an incoherent LED has been used as the excitation source for an organic semiconductor laser. A strategy for further improving the performance of the hybrid device is explored with the use of a luminescent concentrator made of a dye doped SU8 film, to intensify the power density from the inorganic LED. The luminescent concentrator is capable of increasing the incident power density by a factor of 9 and reducing the lasing threshold density by 4.5 times. As a preliminary investigation towards mode-locked polymer lasers, the impact of a solid state saturable absorber on a solution based organic semiconductor laser is explored. The dye doped polystyrene thin film saturable absorber exhibits a saturation intensity of a few MW/cm². When it is placed into the laser cavity, a train of short pulses is generated and the underlying mechanism is discussed. Finally, the potential of using organic semiconductor lasers in the detection of nitro-aromatic explosive vapours is studied in distributed feedback polyfluorene lasers. A high sensing efficiency and fast response from the laser prove polyfluorene lasers can be used as disposal and low cost devices in explosive chemosensing.
Type: Thesis
Publisher: University of St Andrews
Appears in Collections:Physics & Astronomy Theses

This item is protected by original copyright

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.


DSpace Software Copyright © 2002-2012  Duraspace - Feedback
For help contact: | Copyright for this page belongs to St Andrews University Library | Terms and Conditions (Cookies)