Influence of pinhole size and fiber-optic imaging bundle on resolution in confocal endoscopic imaging system

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.