基于片上可印刷回音壁模式聚合物微腔激光器的生化传感研究

On-chip whispering-gallery mode (WGM) optical microcavity as an important sensing element has unique advantage in high-precision biochemical targets detection. The coupling of passive WGM optical microcavities-based biochemical sensors are always realized with the aid of tapered optical fiber or prism by near-field evanescent wave, which could easily increase the difficulty and uncertainty of the resonance measurement under the rigorous and sensitive coupling condition. In order to simplify the fabrication and characterization of device, improve the sensitivity or resolution, and precision of the detection of biochemical targets, the low-cost WGM polymer microcavity lasers are printed by doping gain media in the optical polymer materials in this proposal, which are used for high-precision biochemical sensing with the coupling mechanism of far-field excitation and detection. During the research, the detailed contents include (1) the study of effects of the geometry parameters of the on-chip microcavity on optical parameters of the resonance modes with different polarization states and theoretical analysis of response properties between modes with different polarization states and biochemical targets measured; (2) combining the new optical gain medium and printing technique, the study of low-threshold, high-stability WGM polymer microcavity lasers so as to further improve the Q-factor and excavate potential physical mechanism used for expanding detection flexibility; (3) the study of multi-dimensional far-field biochemical sensing using high-Q lasing property of on-chip microcavity laser.

片上回音壁模式光学微腔作为重要的传感元件，在高精度生化目标探测方面具有独特的优势。基于无源回音壁模式光学微腔的生化传感器往往是借助锥形光纤或棱镜通过近场倏逝波的方式实现光波耦合，严格敏感的耦合条件容易增大谐振测试的难度与不确定性。为了简化器件制作与测试，提高生化目标探测的灵敏度或分辨率，以及准确度，本项目拟通过在光学聚合物中掺杂增益介质的方法，借助远场激发与探测的耦合方式，印刷低成本回音壁模式聚合物微腔激光器，并将其应用于高精度生化传感研究。其中，项目主要内容包括：(1)研究片上微腔几何结构参数对不同偏振态谐振模式光学参量的影响，理论上分析光波偏振态与待测生化目标间的响应特性；(2)结合新型光学增益材料与印刷技术，研究低阈值、高稳定性回音壁模式聚合物微腔激光器，进一步提高Q值，挖掘可拓展探测灵活性的潜在物理机制；(3)利用片上微腔激光器的高Q值激射特性，研究多维度远场生化传感。

片上回音壁模式光学微腔作为重要的传感元件，在高精度生化目标探测方面具有独特的优势。基于无源回音壁模式光学微腔的生化传感器往往是借助锥形光纤或棱镜通过近场倏逝波的方式实现光波耦合，严格敏感的耦合条件容易增大谐振测试的难度与不确定性。为了简化器件制作与测试，提高生化目标探测的灵敏度或分辨率，以及准确度，本项目拟通过在光学聚合物中掺杂增益介质的方法，借助远场激发与探测的耦合方式，印刷低成本回音壁模式聚合物微腔激光器，并将其应用于高精度生化传感研究。其中，项目完成的主要研究内容包括：(1)研究了片上微腔几何结构参数对不同偏振态谐振模式光学参量的影响；(2)结合新型光学增益材料与印刷技术，研究了低阈值、高稳定性回音壁模式聚合物微腔激光器；(3)利用片上新型微腔激光器的高Q值激射特性，研究多维度远场生化传感。最终，验证了量子点微腔激光器优异的远场辐射特性和潜在的生化传感性能，对进一步研发微腔激光器的应用提供了参考。