Experimental Observation of Classical Subwavelength Interference with a Pseudothermal Light Source

We report the experimental observation of classical subwavelength double slit interference with a pseudothermal light source. The experimental results are in good agreement with the theoretical simulation using the second order correlation function for the thermal light.

Figure 1

Sketch of the experimental setup.

Figure 2

Average intensity distributions of the two outgoing beams from the beam splitter for (a) the pseudothermal light and (b) the coherent light. The experimental data are indicated by triangles and circles detected by ${\mathrm{D}}_1$ and ${\mathrm{D}}_2$, respectively. In Figs. 2, 3, 4 the solid lines represent the numerical simulations, and the bandwidth of the thermal light spectrum is taken as $wb/(2\pi )=0.52$.

Figure 3

Interference-diffraction patterns obtained by measuring (a) the normalized joint-intensity correlation function $g^{(2)}(x,-x)$, (b) the joint-intensity correlation fluctuation $\Delta G^{(2)}(x,-x)$, and (c) the joint-intensity correlation $G^{(2)}(x,-x)$ for the pseudothermal light. In (d) the value $G^{(2)}(x,-x)$ is measured for coherent light.

Figure 4

Interference-diffraction patterns obtained by measuring (a) the normalized joint-intensity correlation function $g^{(2)}(x,x)$ of the pseudothermal light, and (b) the joint-intensity correlation function $G^{(2)}(x,x)$ of coherent light.