Conjugated Polymers as Materials for Solid State Lasers

9730126 Heeger半导体聚合物作为潜在的激光材料具有重要的优势，例如高光致发光效率(PL)、低自吸收、发射波长跨越可见光光谱、易于加工成光学质量的薄膜以及在二极管配置中电泵浦。高的光致发光效率和大的受激发射截面一直保持在高浓度。与传统的激光染料不同，共轭聚合物在固体状态下具有高增益激光材料的功能，整齐且未稀释。为了获得较低的阈值和产生相干激光，有必要将共轭聚合物结合到共振结构中。这项研究的目标是通过改进材料和材料工艺以及创造新的谐振结构来实现低阈值光泵浦聚合物激光器。在阈值足够低的情况下，由半导体聚合物制成的激光结构可以发展成连续波激光器。例如，它们可以用常规光源泵浦，或用蓝光LED泵浦(如使用InGaN技术)，或用太阳辐射泵浦(太阳能激光器！)。为了实现这一目标，需要对聚合物材料进行重大改进，以实现所需的高Q共振结构。这些改进和以共轭聚合物为增益介质的高Q共振结构的相关成果是拟议研究的目标。实际工作将包括：测量光泵浦半导体聚合物薄膜的增益和损耗；材料开发，包括制造高质量、低损耗的光学薄膜波导和扩展到新的共轭系统(新的PPV衍生物、聚荧烯衍生物和螺线共轭材料)；包层材料的开发；以及在微腔、分布式反馈结构和“擦环走廊模式”结构(微盘和微环)中对这些共轭材料的评估。这项研究将在激光材料和电活性聚合物领域提供基本的理解和潜在的新的和改进的设备。***

9730126 Heeger Semiconducting polymers offer important advantages as potential laser materials, e.g., High photoluminescence efficiency (PL), low self-absorption, emission wavelengths that span the visible spectrum, easily processed into optical quality thin films, and electrically pumped in a diode configuration. The high PL efficiency and large cross-section for stimulated emission persist to high concentrations. In contrast to traditional laser dyes, conjugated polymers function as high gain laser materials in the solid state, neat and undiluted. To obtain lower thresholds and to generate coherent laser light, it is necessary to incorporate the conjugated polymer into a resonant structure. The goal of this research is to achieve low threshold optically pumped polymer lasers through improvements in materials and materials processing and through the creation of novel resonant structures. With sufficiently low thresholds, lasing structures fabricated from semiconducting polymers can be developed as cw lasers. For example they could be pumped with conventional light sources, or with blue-emitting LEDs (e.g. using the InGaN technology), or with solar radiation (solar powered lasers!). To accomplish this goal, significant improvements in the polymer materials are required to enable the high-Q resonant structures that are needed. These improvements and the related achievement of high-Q resonant structures with conjugated polymers as the gain media are the goals of the proposed research. The actual work will include: measurements of gain and loss in photopumped semiconducting polymer films; materials development including fabrication of high quality, low-loss optical thin film waveguides and expansion into new conjugated systems (new PPV derivatives, polyfluorene derivatives and spiro-conjugated materials); development of cladding materials; and evaluation of these conjugated materials in microcavities, in distributed feedback structures and in `whispe ring gallery mode' structures (micro-disks and micro-rings). %%% This research will provide fundamental understanding and potentially new and improved devices in the area of laser materials and electrically active polymers. ***