Instrument transfer function for digital holography system

Digital holography system can quantitatively obtain the microscopic appearance of the measured surface, with non-contact, high precision, large measuring range, etc. Among the varies of characterizing a system, Instrument Transfer Function (ITF) is the most appealing method, which can describe the system response in terms of an input signal’s frequency content. In this paper, we proposed a method to calculate the system transfer function of digital holography system for measure a high quality phase step, which contains all spatial frequencies. The ITF can be calculated across all frequencies with a single measurement by comparing the Power spectral Density (PSD) of a measured step to the theoretical PSD. The method is applied to calculate the ITF of digital holography system. Experimental result shows that the ITF of the digital holography system is above 60%.The result shows that the ITF of digital holography system could be kept at acceptable levels within the range of interest.Published versio