Fig. 4
From: Shaping the light of VCSELs through cavity geometry design
Spatial coherence analysis of VCSELs with different cavities and their speckles. a Experimental setup for imaging performance assessment, using a 50× objective lens, diffuser, dichroic mirror, and charge-coupled device (CCD) imaging camera to capture images of a standard resolution target and speckle illuminated by each VCSEL. b Sum of the normalized intensity peaks in the emission spectra for each VCSEL geometry. c Imaging patterns of a resolution target under VCSEL illumination, showing the varying levels of speckle for each geometry. d Contrast (C) values calculated from the speckle patterns, indicating spatial coherence levels for each geometry
