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The crystal length modulation for the entangled biphotons generated by SPDC

J. B. WANG1,2, H. B. LIN2,*


  1. College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou 310014, China
  2. Institute of Mechanical & Electrical Technology, Taizhou Vocational & Technical College, Taizhou 318000, China


We demonstrate the quantum entanglement of the entangled biphotons generated by type II spontaneous parametric down-conversion(SPDC) through a nonlinear crystal with phase-matching conditions. We find that the shorter crystal length, makes the main mode be more obvious in the discrete Schmidt modes, and also the corresponding eigenvalues, Weight, and Schmidt Numbers. Hence, shortening of the length of the crystal can further simplify the selection of modes, slightly increase the frequency response range of the down-conversion process, and compress the temporal width of the pulse. Our research is helpful to generate the ultrashort entanglement biphotons in nonlinear optics..


Biphotons, SPDC, Entanglement.

Submitted at: Sept. 21, 2023
Accepted at: April 10, 2024


J. B. WANG, H. B. LIN, The crystal length modulation for the entangled biphotons generated by SPDC, Journal of Optoelectronics and Advanced Materials Vol. 26, Iss. 3-4, pp. 83-90 (2024)