Design of a semi-confocal fluorescence microscope for observing excitation spectrum of soluble molecules adsorbed at the air/water interface

A semi-confocal fluorescence microscope is designed and constructed aiming to observe fluorescence excitation spectrum of soluble molecules adsorbed at the air/water interface. With a conventional confocal fluorescence microscope, the target molecules of pyrene arises some difficulties: excitation wavelength in deep ultraviolet forces low transmission performance of microscopic objectives and low wavelength-tunable performance of an excitation laser. A total internal reflection illumination with a light-guide coupled monochromated-xenon lamp is combined with the confocal fluorescence microscope. Theoretical feasibility and performance of the microscope are discussed with preliminary results obtained.