Nonlinear optical coherence tomography

非线性光学相干断层扫描

• 批准号: 344824-2007
• 负责人: Fraser, James
• 金额: $ 4.9万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments - Category 1 (<$150,000)
• 财政年份: 2006
• 资助国家: 加拿大
• 起止时间: 2006-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=325993
• 关键词: Nonlinear; optical; coherence; tomography

The optical coherence tomography (OCT) microscope can produce micron-scale three-dimensional images to depths of several mm in living tissue.  Though it has made major inroads in ophthalmology, OCT suffers from several difficiencies including low contrast.  We propose to build a new instrument which will exploit the micron-scale resolution capabilities of OCT with the photon selectivity of nonlinear time-gating to improve imaging contrast and decrease data acquisition time.  Subpicosecond optical time gating, by sum-frequency mixing in a nonlinear crystal, rejects light (and its associated noise) from outside the gated time window before detection occurs.  This will yield significant improvements in imaging quality close to highly scattering media and at longer penetration depths.  Aliasing which causes ghost images and noise in current Fourier-domain implementations of OCT will also be avoided.  The time gating process is also beneficial since sample probing can be done with wavelengths around 1300nm which are optimal for sample penetration, while photodetection is done with visible light allowing the use of high performance silicon-based detector technology.  Time gating decreases the number of detector elements required thus dramatically reducing aquisition and processing time compared to standard Fourier-domain OCT systems.     This research program makes extensive use of our preexisting ultrafast infrastructure, our experience with optical pulse characterization, and our collaborations with other OCT researchers, industrial engineers and potential end users.  It is only the first step within an overall vision to integrate ultrafast optical material processing techniques with improved imaging modalities for clinical applications.  Two current graduate students require the equipment immediately for their research program.  An estimated seven additional Queen's students  (undergraduate and graduate) and at least two visiting researchers will have hands-on training on this equipment over the next three years.

光学相干断层扫描（OCT）显微镜可以在活体组织中产生几毫米深度的微米级三维图像。尽管它在眼科领域取得了重大进展，OCT存在对比度低等问题，本文提出了利用OCT的非线性时间选择性，亚皮秒光学时间选通，通过非线性晶体中的和频混频，拒绝轻（及其相关噪音）在探测发生之前，从选通时间窗口之外。这将显著提高接近高散射介质的成像质量，时间选通过程也是有益的，因为样品探测可以用1300 nm左右的波长进行，这对于样品穿透是最佳的，虽然光电检测是利用可见光进行的，允许使用高性能硅，与标准傅立叶域OCT系统相比，时间选通减少了所需的检测器元件的数量，从而显著减少了采集和处理时间。 这项研究计划广泛利用了我们现有的超快基础设施，我们在光脉冲表征方面的经验，以及我们与其他OCT研究人员的合作，工业工程师和潜在的最终用户。这只是将超快光学材料处理技术与临床应用的改进成像模式相结合的总体愿景的第一步。两名目前的研究生立即需要该设备在接下来的三年里，估计还有七名女王大学的学生（本科生和研究生）和至少两名访问研究人员将接受这种设备的实际操作培训。