Nonclassical light in a three-waveguide coupler with second-order nonlinearity

• Published in: EPJ QUANTUM TECHNOLOGY
• Main Authors: Hanapi, Mohd Syafiq M.; Ibrahim, Abdel-Baset M. A.; Julius, Rafael; Choudhury, Pankaj K.; Eleuch, Hichem
• Format: Article
• Language: English
• Published: SPRINGER 2024
• Subjects: Physics; Optics
• Online Access: https://www-webofscience-com.uitm.idm.oclc.org/wos/woscc/full-record/WOS:001290719900001

Possible squeezed states generated in a three-waveguide nonlinear coupler operating with second harmonic generation is discussed. This study is carried out using two well-known techniques; the phase space method (based on positive-P representation) and the Heisenberg-based analytical perturbative (AP) method. The effects of key design parameters were investigated under various conditions, including full frequency matching, symmetrical and asymmetrical waveguide initialization, and both codirectional and contr-adirectional propagation. The system consistently produced long-lasting oscillatory squeezed states across all three waveguides, even when only one waveguide was pumped with coherent light while the others were in a vacuum state. Also, the performance and capacities of both methods are critically evaluated. For low levels of key design parameters and in the early stages of evolution, a high level of agreement between the two methods is noticed. In the new era of quantum-based technology, the proposed system opens a new avenue for utilising nonlinear couplers in nonclassical light generation.