Note: Intro -- Supervisors' Foreword -- Abstract -- Acknowledgments -- Contents -- Publications Relating to this Work -- 1 Introduction -- 1.1…Overview -- 1.2…Organics as Light Sources -- 1.3…The Project -- 1.4…The Thesis -- References -- 2 Theory of Organic Semiconductor Lasers -- 2.1…Introduction -- 2.2…Electronic Properties -- 2.2.1 Conjugated Molecules -- 2.2.2 Energy Levels -- 2.3…Types of Organic Semiconductors -- 2.4…Optical Properties -- 2.4.1 Absorption and Emission of Light -- 2.4.2 Light Amplification in Organic Semiconductors -- 2.5…Organic Semiconductor Lasers -- 2.5.1 Resonators for Organic Lasers -- 2.5.2 Pump Sources for Organic Lasers -- References -- 3 Experimental Methods -- 3.1…Introduction -- 3.2…Thin Film Preparation -- 3.3…Photophysical Characterization -- 3.3.1 Absorption and Photoluminescence Spectroscopy -- 3.3.2 Photoluminescence Quantum Yield -- 3.3.3 PL Lifetime Decay -- 3.3.4 Vase -- 3.4…Amplified Spontaneous Emission -- 3.4.1 ASE Threshold and Linewidth -- 3.4.2 Gain and Loss Coefficients -- 3.5…Distributed Feedback Resonator Fabrication -- 3.5.1 Solvent-Assisted Micro-molding -- 3.5.2 Two-Beam Interference Holography -- 3.5.3 Electron Beam Lithography -- 3.5.4 UV Nanoimprint Lithography -- 3.5.5 Reactive Ion Etching -- 3.5.6 Microstructure Characterization -- 3.6…Organic Semiconductor Laser Characterization -- 3.6.1 Laser Threshold -- 3.6.2 Angle Dependent Emission -- 3.7…Conclusions -- References -- 4 Low-Threshold and Broadly Tuneable Organic Lasers Based on Star-Shaped Oligofluorene Truxenes -- 4.1Introduction -- 4.2Gain Media: Truxene T3 and T4 -- 4.3Photophysical Properties -- 4.4ASE Studies of T3 and T4 -- 4.4.1 ASE Thresholds -- 4.4.2 Gain and Loss -- 4.5Optical Constants -- 4.6Laser Threshold and Tunability Measurement -- 4.7Beyond 3-Armed Truxene-Oligomers -- 4.8Conclusions -- References. , 5 Commercial LED Pumped Organic Semiconductor Lasers -- 5.1…Introduction -- 5.2…Batches of Polymer BBEHP-PPV -- 5.3…Photophysical Studies -- 5.4…ASE Studies of BBEHP-PPV Films -- 5.5…Effect of Molecular Weight -- 5.6…Low Threshold BBEHP-PPV DFB Laser -- 5.6.1 Optimize the Lasing Wavelength -- 5.6.2 Choice of Laser Fabrication Method -- 5.6.3 Optimization of Laser Encapsulation -- 5.7…InGaN LEDs Power Characterization -- 5.8…LED Pumped BBEHP-PPV Lasers -- 5.8.1 Laser Emission Spectra Study -- 5.8.2 Laser Pulse Dynamics Study -- 5.8.3 Laser Beam Divergence Study -- 5.9…Conclusions -- References -- 6 Low Threshold Nanoimprinted Organic Lasers Integration with Micro-LED Arrays -- 6.1…Introduction -- 6.2…Pulsed Micro-LED Power Characterization -- 6.2.1 First Generation Device -- 6.2.2 Second Generation Device -- 6.3…Third Generation Micro-LEDs -- 6.3.1 New Geometry Design -- 6.3.2 Thinned Sapphire Substrate -- 6.3.3 New Driver for the Micro-LEDs -- 6.3.4 Power Output from the Micro-LED Stripes -- 6.4…Pump Beam Shape Dependent Lasing Threshold -- 6.5…Towards Micro-LED Pumped BBEHP-PPV Laser -- 6.6…Laser Resonator Development -- 6.6.1 Mixed-Order DFB Resonator -- 6.6.2 UV Nanoimprint Lithography -- 6.7…Ultra-Low Threshold Nanoimprinted Laser -- 6.8…BBEHP-PPV Laser Pumped by LEDs -- 6.8.1 Commercial LEDs Pumping -- 6.8.2 Micro-LEDs Pumping -- 6.9…Conclusions -- References -- 7 Polymer with Intrinsic Microporosity Used as Explosive Vapour Sensors -- 7.1…Introduction -- 7.2…Sensing Techniques and Principles -- 7.2.1 Main Non-Polymer Sensing Techniques -- 7.2.2 Criteria for an Explosive Sensor -- 7.2.3 Sensing Mechanism in Luminescent Polymers -- 7.3…Polymer with Intrinsic Microporosity -- 7.4…Photophysical and ASE Studies of PIM-1 -- 7.5…Set-Up of Sensing Experiment -- 7.6…PL Sensing Using PIM-1 Films -- 7.6.1 Continuous Sensing -- 7.6.2 Cumulative Sensing. , 7.7…Highly Sensitive Laser Sensor -- 7.7.1 PIM-1 Laser Sensor -- 7.7.2 Comparison with PFO Sensors -- 7.8…Conclusions -- References -- 8 Towards Ultra-Portable Hybrid Organic/Inorganic Explosives Sensing Devices -- 8.1…Introduction -- 8.2…Explosive Sensor Based on a Hybrid Lifetime Micro-System -- 8.2.1 Sensing Based on Fluorescence Lifetime -- 8.2.2 Copolymer ''CDT Green'' -- 8.2.3 Sensor Based on PL -- 8.2.4 Sensing Based on Conventional TCSPC System -- 8.2.5 CMOS Lifetime Analysis Micro-System -- 8.2.6 Ultra-Portable Organic/Inorganic Explosives Sensor -- 8.3…Hybrid Organic Laser Sensor -- 8.4…Conclusions -- References -- 9 Conclusions and Perspectives -- 9.1…Conclusions -- 9.2…Outlook -- References -- Curriculum Vitae.