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 4f system that is described in this paper. Two apertures are set as the input of the 4f 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.