Resonant Transmission of a Light Pulse through a Quantum Well

TL;DR

This paper investigates how a light pulse interacts with a quantum well, focusing on resonant transmission, reflection, and absorption, considering quantum well properties and interface effects.

Contribution

It develops a theory for light pulse interaction with quantum wells of arbitrary width, including effects of interface refraction index differences and multiple excited levels.

Findings

Reflection from quantum well borders varies with pulse frequency and well width.

Additional reflections due to index mismatch significantly alter pulse shape.

Reflection effects disappear at specific frequency-to-width ratios.

Abstract

Reflectance, transmittance and absorbance of a symmetric light pulse, the carrying frequency of which is close to the frequency of interband transitions in a quantum well, are calculated. Energy levels of the quantum well are assumed discrete, and two closely located excited levels are taken into account. The theory is applicable for the quantum wells of arbitrary widths when the size quantization is preserved. A distinction of refraction indices of barriers and quantum well is taken into account. In such a case, some additional reflection from the quantum well borders appears which changes essentially a shape of the reflected pulse in comparison to homogeneous medium. The reflection from the borders disappears at some definite ratios of the carrying frequency of the stimulating pulse and quantum well width.