Optical Design And Construction Of Random-Access Multiphoton Microscopy

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.