Researches On Aberrations And Three-dimensional Transfer Functions In Elliptical Mirror Based Confocal Imaging Microscopy

With the continuous development of the optical microscopy apparatus in the field ofthree-dimensional (3D) imaging, confocal microscopy with its unique ability ofchromatography has become one of the most important analytical instruments in the fieldof surface engineering science and biological engineering. In order to realize3Dmeasurements with high resolution, confocal microscope is developing towards the highphoto efficiency, wide spectrum and short wavelength. Increasing the numerical aperture(NA) of the optical system is an important way to improve the photo efficiency, but thetraditional confocal microscopy techniques exist the theory limit of lens with NA lessthan1, and meantime, due to the influence of the optical properties and materialproperties, the traditional confocal microscopy system has the difficulty of wide spectralimaging chromatic aberration and is difficult to apply to UV or DUV short wave (SW)imaging.The subject “researches on aberrations and three-dimensional transfer functions inelliptical mirror based confocal imaging microscopy” mainly according to the aboveproblems, establish the elliptical mirror based confocal imaging system, carry on theanalysis of elliptical mirror focusing properties and aberration models based on scalardiffraction theory, study3D transfer functions of the elliptical mirror based confocalimaging system and lay the theoretical for developing the elliptical mirror based confocalimaging microscopy. The following are the major issues addressed by this study:Firstly, based on the scalar diffraction theory, provide the apodization function forthe elliptical mirror with a high NA, build the elliptical mirror focusing model upon theDebye approximation scalar diffraction theory and analyze the elliptical mirror focusingfeatures. Analysis results indicate that under the condition of the high NA (NA>0.75), theelliptical mirror focusing ability is better than the lens focusing one with the same NA,and on the other hand, under the condition of the same NA, the beam lobe of the annularaperture elliptical mirror will be further compressed, while the lateral lobe enhanced.Secondly, based on the scalar diffraction theory, in the presence of aberration,establish the diffraction integral formula of the elliptical mirror with a high NA, useZernike circle polynomial to expand the aberration function, emphasis on discussing theimpact of the primary spherical aberration, coma, astigmatism on the focusing characteristics, and in the theory get the elliptical mirror aberration tolerance for theelliptical mirror processing and assembly of the system design to provide the necessarytheoretical basis.Finally, study the3D transfer function of the elliptical mirror based confocalimaging system, by analyzing the3D coherent transfer function of the elliptical mirrorbased confocal imaging microscopy, and further state the optical imaging characteristics.Analysis results show that compared with the conventional confocal system, the ellipticalmirror based confocal imaging microscopy can achieve the expansion of the cutofffrequency of the transfer function, so that strengthen the ability of the high frequencyinformation detection, in theory, can obtain high resolution.