Design and analysis of confocal-spectral microscopyusing wavelength scanning scheme

摘要

The multi-color, or spectral fluorescence microscopy has ability to detect fluorescence spectral signals which are useful in case of studying interactions and phenomena between biological samples. Recently, commercial devices are combining with confocal microscope so to enhance lateral resolution and to have axial direction discernment. Also Acousto-Optic Tunable Filter(AOTF) is used instead of dichroic mirror to divide excitation and emission signals with mininum light efficiency. In addition, AOTF is used in spectral fluorescence microscopy have many advantages, these are very fast switching speed and high resolution in wavelength selection. However it uses acousto-optic interactions in birefringence material, Tellurium Dioxide(TeO_2), the excitation light interacts with appropriate acoustic signal so that it is diffracted to 1 or -1 order path. But the fluorescence signals from a sample propagate in 0 order path with small different angle according to the polarization state. In this paper, a confocal-spectral microscopy is proposed with the new kind of spectral detector design having wavelength scanning galvano mirror. It makes possible to detect broad wavelength fluorescence signal by single PMT with simply rotating the galvano mirror. Also a new birefringent material, calcite(CaCO_3) is used to compensate polarization effect. The proposed spectral confocal microscopy with unique spectrometer body has many advantages in comparison with commercial devices. In terms of detection method, it can be easily applied to other imaging modalities. Hence. this system will be adapted in many applications