Whispering-Gallery Microlaser with Nanocomposite-Film Gain Medium

具有纳米复合膜增益介质的回音壁微型激光器

• 批准号: 0115442
• 负责人: Albert Rosenberger
• 金额: $ 27万
• 依托单位: Oklahoma State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-01 至 2005-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0115442&HistoricalAwards=false
• 关键词: Whispering; Gallery; Microlaser; Nanocomposite; Film

0115442RosenbergerThis project is an investigation of laser action in the whispering-gallery modes (WGMs) of individual fused-silica spherical microresonators (100-1000 um in diameter). The high quality factor (Q) of a microsphere WGM enables lasing with a very low threshold. Using a layer-by-layer assembly process, a microsphere can be coated with a thin polyelectrolyte film containing nanoparticle inclusions of HgTe. The composite film then serves as the gain medium, interacting with the evanescent component of a WGM into which pump laser light is coupled by optical tunneling via a tapered fiber. Pumping with a wavelength around 800 nm can produce lasing in the 1400-1700 nm range, with the laser emission coupled out of the microresonator by the same tapered fiber. The objectives of this project include the following: verify that lasing occurs; optimize the laser output; produce stable, tunable single-mode operation; and concurrentlydevelop the theoretical counterpart, for purposes of guiding the experiment and interpreting its results. To meet these objectives, the PIs previously developed experimental techniques for tuning and frequency-locking the microsphere become invaluable. In this project, light from a probe laser around 1550 nm is coupled into the microsphere to measure optical gain. Then an output threshold is sought, and the coincident linewidth narrowing of the output provides further evidence of lasing. Analysis of the laser output spectrum is performed using a scanning monochromator, a scanning confocal optical spectrum analyzer, and a second tuned microsphere acting as a filter. By compression-tuning the lasing microsphere and using a second microsphere as a filter, tunable single-mode emission can be produced. The theoretical analysis includes an evaluation of the laser threshold and relative gain that is produced in different WGMs under various pumping conditions. Possible mode competition and instability are also explored for normal laser operation and also for the microlaser with injected signal. Two exciting new areas of research are combined here: resonant optical enhancement in microsphere WGMs and easily-fabricated nanocomposite films. The potential impact is great, because a single microlaser can act as a source for 100-channel (or more) wave-division multiplexing. In addition, with the future use of conducting and/or electroluminescent polymers in the film, electrical pumping may replace optical pumping. Such a microlaser can be a tremendous asset to the telecommunications industry. This work continues and expands preliminary exploratory studies, the early results from which are promising. The requested funding is to enable a longer-term (3-year) concerted effort in this area, while providing partial support for the educational and professional development of three Ph.D. candidates, and a hands-on introduction to multidisciplinary experimental and theoretical science for two undergraduates each year.

0115442 Rrosenbergerthis项目是对单个融合 - 硅球形微孔子（直径为100-1000 um）的单个融合 - 硅球形微孔子的窃窃私语模式（WGM）中激光作用的研究。微球WGM的高质量因子（Q）使得阈值非常低。使用逐层组装过程，可以用含有HGTE的纳米颗粒夹杂物的薄聚电解质膜涂上微球。然后，复合膜充当增益介质，与WGM的evaneScent成分相互作用，通过光学隧道通过锥形纤维通过光学隧道耦合到该WGM中。用波长约800 nm的波长在1400-1700 nm范围内产生激光，激光发射通过相同的锥形纤维从微孔子中耦合。该项目的目标包括以下内容：验证激光发生；优化激光输出；产生稳定的可调单模操作；并同时开发理论上的对应物，以指导实验并解释其结果。为了满足这些目标，PIS先前开发了用于调整和锁定微球的实验技术变得无价。在这个项目中，探针激光器的光在1550 nm附近的光线耦合到微球中以测量光学增益。然后寻求输出阈值，并且输出的一致线宽缩小提供了进一步的激光证据。使用扫描单色仪，扫描共聚焦光谱分析仪和第二个调谐的微球用作滤波器，对激光输出光谱进行分析。通过压缩激光微球并使用第二个微球作为滤波器，可以产生可调的单模发射。理论分析包括对在各种泵送条件下在不同WGM中产生的激光阈值和相对增益的评估。还探索了可能的模式竞争和不稳定性，用于正常的激光操作以及带有注射信号的微叠剂。这里结合了两个令人兴奋的新研究领域：微球WGM和易于制作的纳米复合膜中的共振光学增强。潜在的影响很大，因为单个微型播种机可以充当100通道（或更多）波分割多路复用的来源。此外，随着膜中未来使用导电和/或电致电聚合物的使用，电泵可以取代光学泵。这样的微型塑料可能是电信行业的巨大资产。这项工作继续并扩大了初步探索性研究，这是有希望的早期结果。要求的资金是在这一领域实现长期（3年）的一致努力，同时为三个博士学位的教育和专业发展提供部分支持。候选人，以及每年两名本科生的多学科实验和理论科学的动手简介。