Development of a Miniaturized Laser Scanning Microscope

Conclusion: The developed laser scanning microscope shows that the principle of the resonant scanner is working. The advantage of such a scanner is clearly the high speed. But a crucial point is the received Lissajous curve, which demonstrates the bigest disadvante of such a system. The problem of the curve is that the scanning lines do not have a constant distribution. The 90:1 Lissajous figure shows that the lines in the center of the pattern have larger distances to each other than at the right and left sides and the distribution of lines is higher at the turning points of the scanner. The reason for this behaviour is the cosine-like velocity of the scanner, which results in a velocity of zero at the turning points of the scanner and a maximum velocity in the middle of one scan. The result is a different amount of data points at the turning points and in the middle of the pattern and a signal with different sized pulses in time. As discussed, a Ronchi grating would be a possibility to overcome the problem with the cosine velocity and to process the data. Another possibility is to develop a software program that is capable of compensating these different distributions of scanning lines, to obtain an undistorted image. Further, the obtained data from the PDS will generate th information of th eposition of the laser beam across the scan pattern and can then be overlaid with the obtained signal to recieve an undistorted image with position information. These problems will be some of the points for the further development of the setup.

Anothe rpoint for optimizing this setup is that the equipment has to be changed to more expensive and higher quality devices. Therefor, an adequate funding is needed. If this current setup is working as expected with the new equipment, a further research topic will be to miniaturize the setup even more and to use the system as an endocsope for examining living animals.