Integrated Quantum Optoelectronics Lab
Posted on October 22, 2011
The Integrated Quantum Optoelectronics Lab (IQOL) pursues theoretical and experimental investigations of quantum and electromagnetic phenomena in superconducting micro-to-nano scale structures to advance optoelectronic, mm-wave/THz and photonic devices and systems.
Gated Mode Superconducting Nanowire Single Photon Detectors
Single Photon Detectors (SPD) are fundamental to quantum optics and quantum information. Superconducting Nanowire SPDs (SNSPD) [1] provide high performance in terms of quantum efficiency (QE), dark count rate (DCR) and timing jitter [2], but have limited maximum count rate (MCR) when operated as a free-running mode (FM) detector [3, 4]. However, high count rates are needed for many applications like quantum computing [5] and communication [6], a...
Controlling a superconducting nanowire single-photon detector using tailored bright illumination
We experimentally demonstrate that a superconducting nanowire single-photon detector is deterministically controllable by bright illumination. We found that bright light can temporarily make a large fraction of the nanowire length normally-conductive, can extend deadtime after a normal photon detection, and can cause a hotspot formation during the deadtime with a highly nonlinear sensitivity. In result, although based on different physics, the ...
Entangled photon pair generation in hybrid superconductor–semiconductor quantum dot devices
We investigate the effect of Cooper pair injection in shifting the biexciton energy level of low-symmetry (C2v) quantum dots (QDs) exhibiting nontrivial fine structure splitting. Coupling QDs to the superconducting coherent state forms extra fine structures by intermixing the ground and biexcitonic states where spectroscopic separation of neutral exciton and biexciton can be diminished, yielding a system to be utilized in the time reordering sch...
Nonlinearity in single photon detection: modeling and quantum tomography
Single Photon Detectors are integral to quantum optics and quantum information. Superconducting Nanowire based detectors exhibit new levels of performance, but have no accepted quantum optical model that is valid for multiple input photons. By performing Detector Tomography, we improve the recently proposed model [M.K. Akhlaghi and A.H. Majedi, IEEE Trans. Appl. Supercond. 19, 361 (2009)] and also investigate the manner in which these detector...