Single-photon emission in telecommunication band from an InAs quantum dot grown on InP with molecular-beam epitaxy

Abstract

We report on the experimental demonstration of a single-photon source based on an InAs quantum dot (QD) on InP grown by molecular-beam epitaxy emitting in the telecommunication band. We develop a method to reduce the QD density to prevent inter-dot coupling via tunneling through coupled excited states. A single InAs QD embedded in an as-etched pillar structure exhibits intense and narrow emission lines. Photon antibunching is clearly observed using superconducting single-photon detectors with high sensitivity, and further improvement of the generated single-photon purity is demonstrated with below-barrier-bandgap excitation.

Two-photon interference from a bright single-photon source at telecom wavelengths

“…We could improve the indistinguishability using quasi-resonant [14,39,49] or resonant excitation schemes [16][17][18]50], which have already been demonstrated to improve indistinguishability at near infrared wavelengths. We note that InAs/InP quantum dots could potentially emit single photons at 1.5 μm [27,30], so our device and approach could be readily extended to this wavelength range for generating single photons at the c-band. Ultimately, our results show that InAs/InP quantum dots are promising candidates for producing indistinguishable photons for long distance quantum information applications [55,56].…”

“…Quantum dots in III-V semiconductors are particularly promising quantum emitters that generate single photons with high indistinguishability at nearinfrared wavelengths [13][14][15][16][17][18], and are also compatible with electrical injection [19,20] and integration with nanophotonic structures [21][22][23][24]. A number of works have extended the emission of III-V quantum dots to telecom wavelengths by optimizing materials and growth parameters [25][26][27][28][29][30][31]. However, an on-demand source of indistinguishable single photons remains an outstanding challenge at telecom wavelength.…”

Optical observation of superconducting density of states in luminescence spectra of InAs quantum dots

“…The ensemble QD luminescence is generally fitted with the Gaussian function (random energy distribution of individually independent QD emission lines), but each QD emission is intrinsically sharp discrete lines. We observed the QD emission line width of ∼50 μeV from an InAs QD with undoped InGaAlAs barriers grown by MBE in the similar manner on an InP (311)B substrate [44]. Together with the individual sharp QD emission lines, the enhancement of QD luminescence is modified, depending on whether their energies are in resonance or off resonance to the SC DOS, and this results in the sharp edge in the QD luminescence spectra.…”

Electronic and optical properties of InGaAs/GaAs quantum dots with tunable aspect-ratio

“…[1][2][3][4] The InGaAs/GaAs QDs have shown their unique quantum properties in applications of infrared photodetectors, solar cell, and single-photon emitter. [5][6][7][8][9] InGaAs QDs are usually fabricated by the Stranski-Krastanov (SK) epitaxial growth.…”