Fig. 1. Schematic of setup to measure diffraction. BS, 50–50 beam splitter; C.C., coincidence counter.

Fig. 2. Experimental setup for measuring positive and negative correlations in diffraction.

Fig. 3. Experimental results of classical and subwavelength diffraction with thermal light using positive and negative correlatiosn. (a) Classical diffraction obtained with intensity correlation. (b) Subwavelength diffraction obtained with P–N correlation. (c) Comparison of classical and subwavelength diffraction in one dimension. (d) Subwavelength diffraction obtained with different correlations.