Three-dimensional optical transfer function in differential confocal microscopy.
To reveal the fundamental characteristics of differential confocal microscopy (DCM), its imaging properties were analysed by studying the 3D optical transfer function (OTF). The zero transfer at zero frequency along the axial direction in DCM, which has not been well understood and is considerably different from the transfer behaviour in conventional confocal microscopy (CM), was elucidated. The integral expressions of the OTFs for CM and DCM and the subsequent simulation results showed that DCMs have higher transfer capability than CM in the axial direction at medium and high frequencies. Conventionally, the relative optimal defocusing amount in DCMs are determined through calculations of the gradient of the point spread functions in the spatial domain. In contrast, in this study, the OTF performances were compared and the optimal defocusing amount was found to be between 5 and 7.
Ultra-Precision Optoelectronic Instrument Engineering Center, Harbin Institute of Technology, Harbin, China.
J
J
Tan
Ultra-Precision Optoelectronic Instrument Engineering Center, Harbin Institute of Technology, Harbin, China.
H
H
Wang
Ultra-Precision Optoelectronic Instrument Engineering Center, Harbin Institute of Technology, Harbin, China.
M
M
Li
Ultra-Precision Optoelectronic Instrument Engineering Center, Harbin Institute of Technology, Harbin, China.
J
J
Liu
Differential confocal microscopy; optical transfer function; transfer capability