A comparison of digital holographic microscopy and on-axis phase-shifting interferometry for surface profiling

• The aim is a comparison of digital holographic microscopy and on-axis phase-shifting.
• The object is a height-step of 1.34 μm nominally.
• The stability against the environmental disturbance has been assessed.
• The repeatability of the setup has been tested.

This paper presents a quantitative comparison between off-axis digital holographic microscopy (DHM) and on-axis phase-shifting interferometry (PSI) for surface micro topography measurement. The comparison has been applied on an object of a 1.34 μm nominal step height. The experimental results show that single shot, dual-wavelength, off-axis DHM surpasses on dual-wavelength, on-axis PSI in terms of accuracy and repeatability.