Quantum Wire and Quantum Dot Laser

Karl F. Renk

doi:10.1007/978-3-319-50651-7_27

Basics of Laser Physics pp 521-532 | Cite as

Quantum Wire and Quantum Dot Laser

Authors
Authors and affiliations

Karl F. RenkEmail author

Chapter

First Online: 31 March 2017

1.3k Downloads

Part of the Graduate Texts in Physics book series (GTP)

Abstract

The next steps of spatial restriction of free motion of electrons in a semiconductor lead to quantum wire lasers and quantum dot lasers.

Keywords

Quantum Wire Average Electron Density Natural Linewidth Hole Subband Electron Subband

These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

This is a preview of subscription content, to check access.

Problems

27.1

Density of states of electrons in a quantum wire. Derive the density of states of electrons in a quantum wire.

27.2

Absorption by a quantum wire. Estimate the maximum modal absorption coefficient in the case that monochromatic light propagates in an optical waveguide of 0.2 \(\upmu \)m height and 10 \(\upmu \)m width along a quantum wire (\(n =3.5\)). [Hint: assume that the cross section of the GaAs quantum wire shows no variation and that the quantum wire has a low temperature (near 0 K); transitions occur if heavy holes are involved.]

27.3

Calculate the threshold current of a nanolaser that contains one quantum dot and operates (at low temperature) at an occupation number difference \(f_2-f_1=0.8\).

27.4

Bipolar semiconductor laser as a two-level laser. We can describe a bipolar semiconductor laser as a two-level laser. The ground state is the vacuum level \(E_\mathrm{vac, pair}\) of pairs and the excited states are radiative pair states. The pair levels are populated by injection of electrons and holes into the active medium.

(a)

Characterize the density of states of radiative pairs.
(b)

Determine the gain.
(c)

Formulate the condition of gain.
(d)

Apply the bipolar picture to a single radiative pair level in a quantum dot (at low temperature) that is continuously pumped. Determine the lineshape of the radiation emitted by spontaneous electron-hole recombination.

27.5

Laser operating on a naturally broadened line.

(a)

Why is the quantum dot laser (operated at low temperature) so special with respect to line broadening? Is there any other cw laser operating by use of a naturally broadened transition between two laser levels?
(b)

Determine the gain cross section of a quantum dot at low temperature for radiation at a frequency \(\nu =350\) THz.

Copyright information

Authors and Affiliations

Karl F. Renk
- 1
Email author

1.Institut für Angewandte PhysikUniversität RegensburgRegensburgGermany

Quantum Wire and Quantum Dot Laser

Abstract

Keywords

Copyright information

Authors and Affiliations

Personalised recommendations

Cite chapter