Spectral characteristics of chromatic confocal imaging systems

We present signal-generation models for chromatic confocal imaging systems with illumination and detection pinholes of finite size: a collinear model that considers neither aberrations nor diffraction effects, a geometrical model that accounts for aberrations, and a wave optical model covering both aberrations and diffraction effects. These models are aimed at describing the spectral response of multipoint sensor systems with field-dependent aberrations and vignetting effects. They are suitable for single- and double-pass systems with either diffusely or specularly reflecting surfaces under test. We show experimental results to verify our models.