【作者】 占成；

【导师】 骆清铭； 曾绍群；

【作者基本信息】 华中科技大学 ， 生物医学工程， 2006， 硕士

【摘要】 多光子激发扫描成像技术在生命科学研究领域已得到广泛的应用,相比于其他成像技术,多光子激发荧光成像技术对生物体的光损伤小,能够进行深度层析成像和长时间观测,且天然具有高空间分辨率。光学层析能力来自于多光子激发荧光局部激发的特点,只有在激光汇聚焦点位置才能实现多光子荧光激发,而且激发光源为超短脉冲激光。现有的商业化激光扫描显微镜中,一般使用xy扫描镜控制激光束进行扫描,但是每秒只能得到几帧(512×512)图像,远不能满足功能性研究中快事件(ms级甚至μs级)检测的需要。为了对生物领域的快事件进行检测,人们开始尝试开发一种基于二维声光偏转器(acousto-optic deflector ,AOD)的激光扫描显微镜。相比于其他扫描技术,声光偏转器扫描快速(100K)、稳定(无任何机械惯性),而且能实现随机扫描,具有不可替代的功能。本论文详细描述了自行研制的基于二维声光偏转器的多光子随机扫描显微镜的光学设计与构建。通过光学设计,确定了系统的光路,采用通用的光学镜片和调节架完成系统的构建。系统采用单棱镜很好地补偿了二维声光偏转器引起的超短脉冲激光的色散,克服了限制声光偏转器在多光子激发扫描显微镜应用的技术难点,提高了成像的信噪比,而且系统具有高时间分辨率(10μs)和高空间分辨率(<1μm)。目前还没有商业化的多光子随机扫描显微镜,自行研制系统能提前享有多光子随机扫描成像技术的好处,而且花费远低于目前商业化的激光扫描显微镜。在应用上,自行研制的系统也更加灵活,可根据特定的需求对系统做出调整。但目前系统仍是开架式的,占用空间较大,集成度不高。特别是对于只关心其生物应用的研究者,需要将系统进一步集成,做成模块化的产品,方便生物研究者使用。更多还原

【Abstract】 Multiphoton laser scanning microscopy has great future and significant applications in bioscience. Compared with other imaging technology, multiphoton microscopy has many advantages such as low damage to organism, depth tissue imaging, high-resolution, and imaging in-vivo for long time. Multiphoton excitation has femtoliter multiphoton excitation volume, which enables it with optical sectioning capability. The xy mirrors used to be the scanners in common laser scanning microscopy, and the microscopy can acquire only several maps(512×512) per second. Till now, there is no such a laser scanning microscopy that can detect fast signal(ms orμs). In order to study fast events in bioscience, people try to employ two orthogonal acousto-optic deflectors, which steer a pulsed infrared laser beam suited for multiphoton excitation in an inertia-free manner. In this paper, a random-access multiphoton microscopy is described in detail.Through optical design, we discuss how to construct the optical path of the microscopy. The system employs two orthogonal acousto-optic deflectors which will cause significant dispersion. A single prism was inserted into the optical path to compensate the dispersion. After compensation of the dispersion, the signal to noise ratio and the resolution increase significantly.Nowadays, there is still no commercial random-access multiphoton microscopy. It is necessary to develop such a system for researchers in bioscience. And a custom-made system will save much money than buying a commercial laser scanning microscopy.Furthermore, people can change the system according to special requests. Random-access multiphoton is still an open frame system, which is not so convenience to use. A lot of work needs to be done to optimize and module the system.更多还原