Design of real-time confocal microscopy using spectral encoding technique and slit aperture

Abstract

New confocal microscopy having no mechanical beam scanning devices is proposed. The proposed system can get two-dimensional information of a specimen in real-time by using spectral encoding technique and slit aperture. Spectral encoding technique is used to encode one- dimensional lateral information of the specimen in wavelength by a diffraction grating and a broadband light source. The modeling of the optical system is conducted. The effect of slit width variation on the axial response of the system is evaluated by numerical simulation based on the wave optics. Proper width of the slit aperture which plays a crucial role of the out-of-focus blur rejection is determined by a compromise between axial resolution and signal intensity from the simulation result. Design variables and governing equations of the system are derived on the assumption of a lateral sampling resolution of 50 nm. The system is designed to have a mapping error less than the half pixel size, to be diffraction-limited and to have the maximum illumination efficiency. The designed system has a FOV of 12.8 μm x 9.6 μm, a theoretical axial FWHM of 1.1 μm and a lateral magnification of -367.8.