Infrared photodetectors (IRPDs) have become important devices in various applications such as night vision, military missile tracking, medical imaging, industry defect imaging, environmental sensing, and exoplanet exploration. Mature semiconductor technologies such as mercury cadmium telluride and III–V material-based photodetectors have been dominating the industry. However, in the last few de...

The gain-lever effect enhances the modulation efficiency of a semiconductor laser when compared to modulating the entire laser. This technique is investigated in a long-cavity multi-section quantum-dot laser where the length of the modulation section is varied to achieve 14:2, 15:1 and 0:16 gain-to-modulation section ratios. In this work, the gain-levered modulation configuration resulted in an...

Dissertation zur Erlangung des Doktorgrades der Naturwissenschaften ii Zusammenfassung Inhaltsangabe und Zielrichtung der Arbeit Während viele quantenoptische Phänomene in kalten Atomgasen gut etabliert sind, wie der Einzelphotonenemission ('photon antibunching') [1], dem gequetschten Licht ('squeezed light') [2], der Bose-Einstein Kondensation [3], und der Teleportation [4], ste-hen die quante...

We investigate the small-signal modulation response of two-section, gain-lever, quantum-dot semiconductor lasers. A three-polemodulation function is derived from a 3-D set of rate equations, and a 70% 3-dB bandwidth enhancement is computed and experimentally realized in an undoped quantum-dot gain-lever laser under extreme asymmetric-bias conditions. Finally, it is demonstrated that the 3-dB ba...

We propose a new method of generating nonclassical optical field states. The method uses a semiconductor device, which consists of a single quantum dot as active medium embedded in a p- i- n junction and surrounded by a microcavity. Resonant tunneling of electrons and holes into the quantum dot ground states, together with the Pauli exclusion principle, produce regulated single photons or regul...

We report the dispersive readout of the spin state of a double quantum dot formed at the corner states of a silicon nanowire field-effect transistor. Two face-to-face top-gate electrodes allow us to independently tune the charge occupation of the quantum dot system down to the few-electron limit. We measure the charge stability of the double quantum dot in DC transport as well as dispersively v...