Squeezing by multiple higher-harmonic generation

Savita Gill, S. Rani, N. Singh

Sunil Rani, Jawahar Lal, Nafa Singh

Mohammad Zulkarnain Khan Bin Zulkifpeli, Rafael Julius, Abdel-Baset M.A. Ibrahim

Abstract This study investigates the squeezing properties of light across a two-octave system consisting of multichannel single-mode nonlinear waveguides with evanescent coupling. The focus is on the first, second, and fourth harmonics generation. We analyze different input combinations and coupling setups to gain insight into how they impact the level of squeezing. The results show that multiple initial inputs amplify the squeezing effect, while certain initialization setups help maintain squeezing at higher harmonic levels. When the waveguides are fully coupled in the first octave, there is a large increase in squeezing at the first and second harmonic. Reduced coupling leads to a drop in the level of squeezing. At the fourth harmonic frequency, instability is observed in all configurations, which hinders the accurate detection of squeezing. By optimizing the quantity and arrangement of interconnected waveguides, it is possible to improve the nonlinear frequency conversion and thus the level of squeezing. This research may enhance the advancement of quantum optical systems by emphasizing the significance of coupling interactions across two harmonic generations.

M. Kozierowski

Hong and Mandel's concept of higher-order squeezing is applied to higher-harmonic generation (k\ensuremath{\ge}2). The fundamental mode is shown to be intrinsically squeezed to the order k of the process for even k and to the order of k-1 for odd k.

You-Bang Zhan

Mohammad Zulkarnain Khan Bin Zulkifpeli, Rafael Julius

This paper investigates the squeezing properties and harmonic generation in a two-octave nonlinear waveguide system composed of channels exhibiting a second-order nonlinear effect. The channel converts an input frequency at the first harmonic to the second and subsequently to the fourth harmonic. The system equation is solved semi-analytically by using the normal ordered phase space representation. The results show consistent first harmonic squeezing across channels, while second and fourth harmonic squeezing vary significantly, with the center channels showing higher efficiency. As the harmonic generation progresses from the first harmonic to the fourth harmonic, the magnitude of squeezing typically decreases. These findings may provide valuable findings for enhancing higher-order harmonic generation and squeezing in nonlinear waveguide systems.