Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userAn efficient, tunable, and robust source of narrow-band photon pairs at the $^{87}$Rb D1 line
57
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We present an efficient and robust source of photons at the $^{87}$Rb D1-line (795 nm) with a narrow bandwidth of $delta=226(1)$ MHz. The source is based on non-degenerate, cavity-enhanced spontaneous parametric down-conversion in a monolithic optical parametric oscillator far below threshold. The setup allows for efficient coupling to single mode fibers. A heralding efficiency of $eta_{mathrm{heralded}}=45(5)$ % is achieved, and the uncorrected number of detected photon pairs is $3.8 times 10^{3}/(textrm{s mW})$. For pair generation rates up to $5times 10^{5}/$s, the source emits heralded single photons with a normalized, heralded, second-order correlation function $g^{(2)}_{c}<0.01$. The source is intrinsically stable due to the monolithic configuration. Frequency drifts are on the order of $delta/20$ per hour without active feedback on the emission frequency. We achieved fine-tuning of the source frequency within a range of $ > 2$ GHz by applying mechanical strain.
rate research
Read More
The spectrum width can be narrowed to a certain degree by decreasing the coupling strength for the two-level emitter coupled to the propagating surface plasmon. But the width can not be narrowed any further because of the loss of the photon out of system by spontaneous emission from the emitter. Here we propose a new scheme to construct a narrow-band source via a one-dimensional waveguide coupling with a three-level emitter. It is shown that the reflective spectrum width can be narrowed avoiding the impact of the loss. This approach opens up the possibility of plasmonic ultranarrow single-photon source.
The frequency correlation (or decorrelation) of photon pairs is of great importance in long-range quantum communications and photonic quantum computing. We experimentally characterize a spontaneous parametric down conversion (SPDC) source, based on a Beta-Barium Borate (BBO) crystal cut for type-II phase matching at 1550 nm which emits photons with the positive or no spectral correlations. Our system employs a carefully designed detection method exploiting two InGaAs detectors.
We propose a scheme for the generation of counterpropagating polarization-entangled photon pairs from a dual-periodically poled crystal. Compared with the usual forward-wave type source, this source, in the backward-wave way, has a much narrower bandwidth. With a 2-cm-long bulk crystal, the bandwidths of the example sources are estimated to be 3.6 GHz, and the spectral brightnesses are more than 100 pairs/(s GHz mW). Two concurrent quasi-phase-matched spontaneous parametric down-conversion processes in a single crystal enable our source to be compact and stable. This scheme does not rely on any state projection and applies to both degenerate and non-degenerate cases, facilitating applications of the entangled photons.
Quantum technology requires the creation and control over single photons as an important resource. We present a single photon source based on a single molecule which is attached to the end-facet of an optical fiber. To realize a narrow linewidth, the system is cooled down to liquid-helium temperatures. The molecule is optically excited and its fluorescence is collected through the fiber. We have recorded an excitation spectrum, a saturation curve and analyzed the contributions of Raman background fluorescence. This presents to date the crucial limit for the introduced device. The single photon nature is proven by an anti-bunched auto-correlation recording, which also shows coherent Rabi oscillations.
The implementation of fiber-based long-range quantum communication requires tunable sources of single photons at the telecom C-band. Stable and easy-to-implement wavelength- tunability of individual sources is crucial to (i) bring remote sources into resonance, to (ii) define a wavelength standard and to (iii) ensure scalability to operate a quantum repeater. So far, the most promising sources for true, telecom single photons are semiconductor quantum dots, due to their ability to deterministically and reliably emit single and entangled photons. However, the required wavelength-tunability is hard to attain. Here, we show a stable wavelength-tunable quantum light source by integrating strain-released InAs quantum dots on piezoelectric substrates. We present triggered single-photon emission at 1.55 {mu}m with a multiphoton emission probability as low as 0.097, as well as photon pair emission from the radiative biexciton-exciton cascade. We achieve a tuning range of 0.25 nm which will allow to spectrally overlap remote quantum dots or tuning distant quantum dots into resonance with quantum memories. This opens up realistic avenues for the implementation of photonic quantum information processing applications at telecom wavelengths.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
