The coupling gain coefficient g is redefined and deduced based on coupling theory, the variant of coupling gain
coefficient g for different ΓL and r is analyzed. A new optical system is proposed for image edge-enhancement. It
recycles the back signal to amplify the edge signal, which has the advantages of high throughput efficiency and
brightness. The optical system is designed and built, and the edge-enhanced image of hand bone is captured
electronically by CCD camera. The principle of optical correlation is demonstrated, 3-D correlation distribution of letter
H with and without edge-enhancement is simulated, the discrimination capability Iac and the full-width at half
maximum intensity (FWHM) are compared for two kinds of correlators. The analysis shows that edge-enhancement
preprocessing can improve the performance of correlator effectively.
The signal intensity is derived firstly on the basis of point spread function. Then the effect of pinhole radius on
resolution is discussed for different central obstruction rate
ε. According to the simulated plots, the optimum
relationship of axial resolution to pinhole radius and central obstruction rate ε is proposed. Finally the confocal
imaging system is designed and established. The axial response is measured for different pinhole radius.
Experimental results agree well with theoretical analysis. The in-focus images of bar target is obtained by the
confocal imaging system which shows good performance
A novel endoscopic confocal imaging system is presented by modifying the conventional laser confocal scanning
microscope. Based on point spread function and Fourier optics, the coherent transmission function of the system is
derived and the influence of fiber on axial resolution is investigated in detail. It is shown that the system acts as a
coherent imaging system and the axial resolution of the system decays with increasing fiber radius A. Finally, an
endoscopic confocal imaging system was built, and the in-focus and out-of-focus images of glass grating are obtained,
which show good lateral resolution.
A novel confocal endoscopic imaging system is designed for imaging thick sample. The lateral and axial detected image intensity is deduced and calculated based on point spread function (PSF). The analysis of influence of pinhole and fiber on resolution is given. Our researches show that the lateral resolution improvement is much more sensitive to pinhole size than the axial resolution. Confocal system has narrower half width at half maximum (HWHM) and higher lateral and axial resolution for smaller pinhole. At last a criterion for pinhole size is introduced first of all to ensure confocal imaging and maximize signal-to-noise ratio, which is very helpful in the practical design of confocal endoscopic imaging system.
Coupling theory is employed to analyze the coupling gain and a novel optical system is presented for image edge-enhancement by employing photorefractive two-wave coupling in BaTiO3 crystal, in which the ordinarily discarded background light is recycled as the pump source to amplify the signal light. Further, we demonstrate the principle of optical correlation and compare the discrimination capability of two kinds of correlators by computer simulation, in one of which input images are edge-enhanced and in the other the ones do not experience edge-enhancement. At last, we draw a conclusion that edge-enhancement preprocessing can improve discrimination capability effectively.