Single-pixel hyperspectral photoluminescence tomography of optical materials

Three-dimensional photoluminescence (PL) imaging at micrometer scales is essential for characterizing defects in optical materials. However, conventional scanning systems suffer from prohibitively long acquisition times when measuring weak PL signals from defects. We present a novel 3D compressive imaging technique, to our knowledge, that extends single-pixel camera principles to volumetric PL tomography, achieving three-dimensional reconstruction with micrometer-scale depth resolution. This is enabled by a set of unique 3D speckle patterns generated near the focal plane of a lens, exploiting their rapid decorrelation in the near-field diffraction regime. Theoretical analysis confirms that the depth resolution follows conventional depth of field scaling laws while enabling simultaneous acquisition of entire 3D datasets. We demonstrate the method's capability using Ce-doped luminophore plates, successfully distinguishing multiple PL sources within the same volume and accurately tracking their positions along the laser beam. The approach offers significant potential for studying bulk and surface defects in optical materials.