PPKTP Crystal Options
PPKTP Crystal Options
Blog Article
Entangled photon pairs can be a essential resource in quantum communication protocols ranging from quantum critical distribution to teleportation. The current workhorse method for generating photon pairs is through spontaneous parametric down conversion (SPDC) in bulk nonlinear crystals.
Case in point: One PPKTP crystal can be employed inside of a quantum entanglement set up to produce pairs of photons with high efficiency and purity.
Large efficiency: periodic poling can attain increased conversion effectiveness as a result of a chance to obtain the very best nonlinear coefficient along with the absence of spatial walk-off.
Current quantum computing efforts by Xanadu [4] and QuiX [5] utilized ppKTP at the identical wavelength area, because of both bigger purity at these wavelengths and compatibility with peripheral platforms for example Silicon Nitride. Raicol has developed (via a collaboration with Prof. Ady Arie) a method for the look and manufacture of significant spectral purity apKTP crystals for Boson sampling and quantum interference close to the team velocity matching stage of 1550nm.
When choosing a crystal for squeezed mild apps, the researcher ought to initial choose In the event the squeezing will likely be produced in single-go or within a cavity.
Additional, the waveguide may be used in both the Sagnac or single-move configuration with put up-choice to deliver polarization entanglement along with spectral purity concurrently. The comparison between our analytical expression of Schmidt decomposition and the precise numerical Alternative is completed by thoroughly finding out the result of pump bandwidth and waveguide size on Schmidt range and spectral purity. The effects highlight that, in general, the analytical formula marginally overestimates the purity, but the two solutions converge Should the contribution of side lobes arising in the section-matching perform is minimized. Last but not least, we review the effect of scattering losses (ensuing from the fabrication imperfections) to the spectral purity of your biphoton point out. Our proposed on-chip supply might have purposes in quantum communication, photonic quantum computing, quantum information processing, and quantum metrology.
Look at now a sort-II downconversion in which signal and idler radiation are orthogonally polarised and determine, with out lack of generality, the sign photons being polarised horizontally.
In summary, We have now demonstrated a polarization-entangled photon resource using a PPKTP crystal inside of a Sagnac interferometer configuration. The PPKTP crystal satisfies the GVM condition at telecom wavelengths, therefore, the intrinsic spectral purity is way bigger than that within the near-infrared wavelength variety. We have now realized click here visibilities of around 96% in quantum correlation measurement, an S price of 2.
tunability, and spatially characterize the supply with regard to the photon pairs produced in collinear
Evaluating our scheme Along with the prior entangled photon source with a GVM-PPKTP crystal inside a calcite beam displacer configuration at telecom wavelength [thirty], our count prices are much more than a hundred instances higher, largely owing to our extremely efficient SNSPDs and fine alignment in Sagnac-loop.
Our condition-of-the-artwork amenities and dedication to innovation make sure just about every PPKTP crystal meets the highest criteria of efficiency and reliability.
Particularly, ferro-electric poling on the crystal is utilized to toggle d eff concerning beneficial and damaging values in integer multiples of a particular duration along the crystal, the poling periodicity Λ. Look at a collinear course of action where by pump, signal and idler Just about every propagate along the crystal’s x-axis. The amplitude for a downconversion in the crystal with length L reads
Later on, this polarization-entangled photon source will probably be useful for many different purposes in quantum information and interaction at telecom wavelengths. For example, this supply is instantly applicable to absolutely free Area quantum essential distribution at telecom wavelengths and brief length fiber communications.
A great alignment with the Sagnac loop is not easy. Therefore, we come up with a mathematical simulation [forty four] to simulate the beam propagations in a very triangle form Sagnac-loop. From this simulation, we could find out that the output beams are always in parallel, but in no way cross. As a way to obtain a very collinear configuration for both equally the CW and CCW pump beams, the residual pump beams should overlap Together with the input laser.
To produce factors a little bit more intricate, the dispersion and also the length with the KTP crystal also influences the spectral bandwidth and pair rate.