Coherence measurement with digital micromirror device

Abstract

We measure the complex-valued spatial coherence function of a multimode broad-area laser diode using Young's classical double slit experiment realized with a digital micromirror device. We use this data to construct the coherent modes of the beam and to simulate its propagation before and after the measurement plane. When comparing the results to directly measured intensity profiles, we find excellent correspondence to the extent that even small details of the beam can be predicted. We also consider the number of measurement points required to model the beam with sufficient accuracy.

Spatial coherence measurement and partially coherent diffractive imaging using self-referencing holography

“…Eq. (6) indicates that the correlation is maximal when the two coordinates of the MCF coincide (r 0 ± r = r 0 ), so the peak of the correlation function will always appear at the origin (r = 0). We observe in the figure that as we move r 0 further from the origin, the area of measurement shifts further too.…”

“…The spatial coherence of a beam is described by the complexvalued 4-dimensional mutual coherence function (MCF). The process of measuring the MCF is time consuming, especially for methods measuring the intensity-intensity correlation [1,2] or the interference pattern [6] at all pairs of locations. Other interference based methods measure the fringe visibility in a single direction [7][8][9] or multiple directions [10,11].…”

Tailoring light with a digital micromirror device

“…The spatial coherence of light is characterized by the visibility of fringes in Young's interference experiment. The problem is how to flexibly regulate the distance between slits.…”

“…A series of transverse laser modes were created with a DMD, including the Laguerre–Gaussian beam, Ince–Gaussian modes, nondiffracting beams, as well as cylindrically symmetric vector‐vortex beams. The DMD with reprogrammable ability provides easily adjustable Young's double slits in optical coherence measurements.…”

Agile wavefront splitting interferometry and imaging using a digital micromirror device

“…More recently in 2009, we proposed the use of the DMD to realize wavefront splitting interferometers as well as a variety of imagers [34]. Very recently, this DMD-based Young's double slit interferometer design has been used to measure spatial coherence of a light source [35] and optical field values at a sample plane [36]. In this paper, we describe our proposed original SLMbased interferometer and imager designs and the basic experimental results by our Ref.…”