Abstract

We report detailed experimental studies in a single wavelength-band system of correlated photon-pair generation in a 1.5 μm telecommunication wavelength-band using cascaded ${\chi }^{(2)}:{\chi }^{(2)}$ processes, second-harmonic generation, and the following spontaneous parametric down conversion (c-SHG/SPDC), in a periodically poled ${\mathrm{LiNbO}}_3$ (PPLN) ridge-waveguide device. By using a PPLN module with $600\%/W$ of the SHG efficiency, we achieved a coincidence-to-accidental ratio (CAR) of 2380 at $1.8\times {10}^{-4}$ of the mean number of the signal photon per pulse. Detailed investigation on the origin of uncorrelated noise photons was also discussed in this paper. We revealed that the noise photons mainly originated from spontaneous Raman scattering induced in pigtail optical fibers and also that the PPLN device itself had poor contribution to the noise photons. This feature of the c-SHG/SPDC process is promising for the realization of a noise-photon-free, high-purity quantum entangled photon-pair source.

©2012 Optical Society of America

Generation of polarization entangled photon pairs at telecommunication wavelength using cascaded χ⁽²⁾ processes in a periodically poled LiNbO₃ ridge waveguide

Shin Arahira, Naoto Namekata, Tadashi Kishimoto, Hiroki Yaegashi, and Shuichiro Inoue
Opt. Express 19(17) 16032-16043 (2011)

1.5-μm band polarization entangled photon-pair source with variable Bell states

Shin Arahira, Tadashi Kishimoto, and Hitoshi Murai
Opt. Express 20(9) 9862-9875 (2012)

Experimental investigation in transmission performance of polarization-entangled photon-pairs generated by cascaded χ⁽²⁾ processes over standard single-mode optical fibers

Shin Arahira and Hitoshi Murai
Opt. Express 20(14) 15336-15346 (2012)

Nearly degenerate wavelength-multiplexed polarization entanglement by cascaded optical nonlinearities in a PPLN ridge waveguide device

Shin Arahira and Hitoshi Murai
Opt. Express 21(6) 7841-7850 (2013)

Generation of high-purity entangled photon pairs using silicon wire waveguide

Ken-ichi Harada, Hiroki Takesue, Hiroshi Fukuda, Tai Tsuchizawa, Toshifumi Watanabe, Koji Yamada, Yasuhiro Tokura, and Sei-ichi Itabashi
Opt. Express 16(25) 20368-20373 (2008)