Robust, high brightness, degenerate entangled photon source at room temperature

Abstract We report on a compact, simple and robust high brightness entangled photon source at room temperature. Based on a 30-mm-long periodically-poled potassium titanyl phosphate crystal, the source produces non-collinear, type-0, phase-matched, degenerate photons at 810 nm with spectral brightnes...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: M. V. Jabir, G. K. Samanta
Formato: article
Lenguaje:EN
Publicado: Nature Portfolio 2017
Materias:
R
Q
Acceso en línea:https://doaj.org/article/3897b2f917544feebd599e972edf9f1a
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
Descripción
Sumario:Abstract We report on a compact, simple and robust high brightness entangled photon source at room temperature. Based on a 30-mm-long periodically-poled potassium titanyl phosphate crystal, the source produces non-collinear, type-0, phase-matched, degenerate photons at 810 nm with spectral brightness as high as ~0.41 ± 0.02 (~0.025 ± 0.02) MHz/mW/nm for multi (single) mode fiber coupling. So far, this is the highest number of degenerate photons generated using a continuous-wave laser pumped bulk crystal and detected using multimode fiber. We have studied the dependence of pump focusing on the brightness of the generated photons collected using both multimode, and single mode fibers. For a fixed pump power and crystal parameters, the SPDC source has an optimum pump waist radius producing maximum number of paired photons. Combining the crystal in a novel system architecture comprised with Sagnac interferometer and polarizing optical elements, the source produces polarization entangled photon states with high spectral brightness. Even in the absence of any phase compensation, the entangled photon states detected using single mode fiber have a Bell’s parameter, S = 2.63 ± 0.02, violating the Bell’s inequality by nearly 32 standard deviations and fidelity of 0.975. The compact footprint, robust design, and room temperature operation, make our source ideal for various quantum communication experiments.