Off-axis common-path digital holography using a cube beam splitter

Abstract

An off-axis common-path digital holography is built up by inserting a 45° tilted cube beam splitter (CBS) into a 4 f system that is described in this paper. Two apertures are set as the input of the 4 f system, where one supports the object, and the other is vacant. The CBS divides the incoming beam into two copies, which are symmetrical with each other along the semi-reflecting layer. Due to the separation of two beams in a Fourier plane and the flipping of the field of view induced by the CBS, an off-axis hologram can be captured. Moreover, the carrier frequency can be easily modulated by translating the CBS perpendicular to the optical axis. The new proposed scheme has high light utilization, a compact setup, and high temporal stability. The experiments are carried out to demonstrate the validity and stability of the proposed method.