Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Optics Express

Bright two-color tripartite entanglement with second harmonic generation

Shuqin Zhai, Rongguo Yang, Kui Liu, Hailong Zhang, Junxiang Zhang, Jiangrui Gao

Published May 27, 2009• 16 citations
Publisher

Abstract

The bright two-color tripartite entanglement is investigated in the process of type II second harmonic generation (SHG) operating above threshold. The two pump fields and the second harmonic field are proved to be entangled, and the dependence of the entanglement degree on pump parametersigma and normalized frequency Omega is also analyzed.

DOI
10.1364/oe.17.009851

Related papers

Tripartite entanglement from the cavity with second-order harmonic generation

Shuqin Zhai, Rongguo Yang, Daihe Fan +4 more

In this paper, tripartite entanglement among the two pump fields and the second-order harmonic field is established in the process of type-II second-order harmonic generation (SHG) with a triply resonant optical cavity below threshold. A sufficient inseparability criterion for continuous-variable tripartite entanglement proposed by van Loock and Furusawa is used to evaluate the degree of the quadrature--phase-amplitude correlations between the three modes. The dependence of the entanglement on the pump parameter and analysis frequency is also discussed. It is shown that the best entanglement appears at the appropriate pump power and analysis frequency. These three entangled states with different frequencies generated directly from a simple SHG process make the scheme useful for the application in quantum communication and network.

Physical Review A•Jul 9, 2008•31 citations

Quadripartite entangled state from cascaded second-harmonic generation

Rui Yang, Shuqin Zhai, Rongguo Yang

A generation system of continuous-variable (CV) quadripartite entangled state based on two cascaded second-harmonic generation (SHG) cavities below the threshold is investigated. Two reflected fundamental beams of the first cavity, the reflected second-harmonic beam and the output fourth-harmonic beam of the second cavity are proved to be entangled, and the dependence of the entanglement degree on the normalized frequency, pump parameter, fourth-harmonic loss parameter, and second-harmonic loss parameter is also analyzed. Due to the fact that the cavity parameters and the nonlinear crystals of the two SHG cavities can be freely chosen, the practicality of the proposed protocol is relatively perfect and the system can also be extended to the preparation of multicolor entangled states for a quantum network.

Chinese Physics B•Apr 1, 2014•1 citation

Bright entanglement characteristics of subharmonic modes reflected from cavity for type II second-harmonic generation

Zehui Zhai, Hongxin Zou, Junxiang Zhang +1 more

Quantum fluctuation and quantum entanglement in competing nonlinear processes of type II second-harmonic generation in a triple-resonant cavity is analyzed. Operating above threshold with intracavity loss, the mean amplitude and the entanglement of reflected subharmonic field as a function of pump and loss parameters are calculated. It is found that the two eigenmodes become unbalanced when internal loss intervenes. The dependence of the entanglement characteristics of two reflected subharmonic modes on output coupling efficiency µ_b/µ, pump parameter sigma, and normalized frequency Omega are discussed. Under appropriate conditions, this system can be exploited as a bright entanglement resource.

Journal of the Optical Society of America B•Apr 1, 2005•2 citations

Generation of multicolored tripartite entanglement by frequency doubling in a two-port resonator

Rongguo Yang, Shuqin Zhai, Kui Liu +2 more

Multicolored multipartite entanglement is of great importance in quantum communication and quantum information networks. In this paper, we calculate the quantum fluctuations of the fundamental frequency pump beam and second-harmonic beams in a two-port frequency doubling resonator, and investigate the tripartite continuous-variable entanglement generated by this device for the first time, to our knowledge. The quantum correlation among fundamental frequency pump beam and two harmonic beams is studied using a necessary and sufficient criterion for Gaussian entanglement states, the positivity under partial transposition. It is found that two-color tripartite entanglement exists in a large range of pump intensities and analysis frequencies.

Journal of the Optical Society of America B•Nov 16, 2010•6 citations

Bright Entangled Beams from an Above-Threshold Optical Parametric Oscillator

K. N. Cassemiro, Alessandro S. Villar, Paulo Valente +2 more

We generated bright entangled beams in an optical parametric oscillator, operating above threshold. Tripartite pump-signal-idler entanglement, all with different frequencies, was also predicted and three-color quantum correlations already measured.

The Rochester Conferences on Coherence and Quantum Optics and the Quantum Information and Measurement meeting•Jan 1, 2007•1 citation

Bright three-color continuous-variable entanglement produced by quasi-phase-matched third-harmonic generation

Youbin Yu, Huaijun Wang

We presented a scheme to produce bright three-color continuous-variable (CV) entanglement by cascaded quasi-phase-matched sum-frequency processes. Second- and third-harmonic fields are generated by two sum-frequency processes,respectively. The fundamental, second-, and third-harmonic fields are CV entangled with each other by applying the necessary and sufficient CV entanglement criterion. The relations between the entanglement features of the three beams and nonlinear coupling parameters and damping rates are also discussed.

International Conference on Multimedia Technology (ICMT)•Jul 1, 2011•0 citations
The bright two-color tripartite entanglement is investigated in the process of type II second harmonic generation (SHG) operating above threshold. The two pump fields and the second harmonic field are proved to be entangled, and the dependence of the entanglement degree on pump parametersigma and normalized frequency Omega is also analyzed.
In this paper, tripartite entanglement among the two pump fields and the second-order harmonic field is established in the process of type-II second-order harmonic generation (SHG) with a triply resonant optical cavity below threshold. A sufficient inseparability criterion for continuous-variable tripartite entanglement proposed by van Loock and Furusawa is used to evaluate the degree of the quadrature--phase-amplitude correlations between the three modes. The dependence of the entanglement on the pump parameter and analysis frequency is also discussed. It is shown that the best entanglement appears at the appropriate pump power and analysis frequency. These three entangled states with different frequencies generated directly from a simple SHG process make the scheme useful for the application in quantum communication and network.
A generation system of continuous-variable (CV) quadripartite entangled state based on two cascaded second-harmonic generation (SHG) cavities below the threshold is investigated. Two reflected fundamental beams of the first cavity, the reflected second-harmonic beam and the output fourth-harmonic beam of the second cavity are proved to be entangled, and the dependence of the entanglement degree on the normalized frequency, pump parameter, fourth-harmonic loss parameter, and second-harmonic loss parameter is also analyzed. Due to the fact that the cavity parameters and the nonlinear crystals of the two SHG cavities can be freely chosen, the practicality of the proposed protocol is relatively perfect and the system can also be extended to the preparation of multicolor entangled states for a quantum network.
Quantum fluctuation and quantum entanglement in competing nonlinear processes of type II second-harmonic generation in a triple-resonant cavity is analyzed. Operating above threshold with intracavity loss, the mean amplitude and the entanglement of reflected subharmonic field as a function of pump and loss parameters are calculated. It is found that the two eigenmodes become unbalanced when internal loss intervenes. The dependence of the entanglement characteristics of two reflected subharmonic modes on output coupling efficiency µ_b/µ, pump parameter sigma, and normalized frequency Omega are discussed. Under appropriate conditions, this system can be exploited as a bright entanglement resource.
Multicolored multipartite entanglement is of great importance in quantum communication and quantum information networks. In this paper, we calculate the quantum fluctuations of the fundamental frequency pump beam and second-harmonic beams in a two-port frequency doubling resonator, and investigate the tripartite continuous-variable entanglement generated by this device for the first time, to our knowledge. The quantum correlation among fundamental frequency pump beam and two harmonic beams is studied using a necessary and sufficient criterion for Gaussian entanglement states, the positivity under partial transposition. It is found that two-color tripartite entanglement exists in a large range of pump intensities and analysis frequencies.
We presented a scheme to produce bright three-color continuous-variable (CV) entanglement by cascaded quasi-phase-matched sum-frequency processes. Second- and third-harmonic fields are generated by two sum-frequency processes,respectively. The fundamental, second-, and third-harmonic fields are CV entangled with each other by applying the necessary and sufficient CV entanglement criterion. The relations between the entanglement features of the three beams and nonlinear coupling parameters and damping rates are also discussed.