Coherence imaging for laser detection

The detection of lasers by means of coherence detection often uses interferometry in a one-dimensional manner such as with a Mach Zehnder interferometer. We are taking a two dimensional approach making use of a spatial light modulator and a camera to examine the results of binary holography in differentiating coherent and incoherent incoming light. A DMD micromirror array focusing light onto a CCD camera is presented as a method for determining the presence of coherent light, its wavelength and angle of arrival. We discuss the use of Zernike modes to overcome the aberrations inherent in the DMD device, thereby improving the focussing quality and improving the precision of wavelength determination.