Propagation of nonclassical optical radiation through a semiconductor slab

Based on a microscopic derivation of the emission spectra of a bulk semiconductor, we arrive at a clear physical interpretation of the noise current operators in macroscopic quantum electrodynamics. This opens the possibility to study medium effects on nonclassical radiation propagating through an absorbing or amplifying semiconductor. As an example, the propagation of an incident squeezed vacuum is analyzed.

Figure 1

Output squeezing spectrum for a GaAs slab $(L=25\mu \mathrm{m})$ near the $1s$-excitonic resonance (indicated by an arrow) of $\text{bandwidth}=0.2\mathrm{meV}$. The squeezing spectrum with squeezing strength $\mid \xi \mid =0.2$ is shown for temperature $T=3\mathrm{K}$ (a), and $T=300\mathrm{K}$ (b). The dot-dashed and solid lines indicate the maximum $\left(S_{\mathrm{sq}}^{\max }\right)$ and minimum $\left(S_{\mathrm{sq}}^{\min }\right)$ noise level of the squeezed field, respectively. The gray background shows the emission spectrum $S_{\mathrm{em}}$. Horizontal dashed lines represent the maximum and minimum noise level of the squeezed input field.

Figure 2

Output squeezing spectrum for a slab with the same model parameters as in Fig. 1. The squeezing strength parameter is $\mid \xi \mid =1.2$, all other conditions are the same as in Fig. 1.

Figure 3

Squeezing spectrum after transmission of a GaAs slab at temperature $T=3\mathrm{K}$, pumped to a carrier density of $n=3\times {10}^{16}{\mathrm{cm}}^{-3}$ (a), and the corresponding imaginary part of susceptibility (b). The output squeezing spectra are shown for minimum (full line) and maximum (dot-dashed line) noise levels. The input (dashed) squeezing spectra are shown for $\mid \xi \mid =0.2$. The emission spectrum is shown by the grey beckground. An arrow in (b) indicates the chemical potential $\mu$ and the inset in (a) shows the squeezing spectra in its vicinity.