Fundamental properties and applications of Lithium Tantalate (LiTaO3) photonic integrated circuits for nonlinear dynamics and electro-optical frequency combs
Abstract
Asymmetric transmission (AT) of light, especially unidirectional propagation, plays a critical role in developing optical communications, laser technologies, shielding and photovoltaic devices. In recent years, several approaches have been proposed to achieve this goal. Even with these noteworthy advances, creating AT devices that are compact, efficient, completely passive, self-activating, and easy to manufacture remains a significant challenge. This project aims to investigate a new approach to achieve unidirectional light propagation based on parity-time (PT) symmetry breaking of reflectionless modes. The practical embodiment is a high-power optical isolator with a wide range of operating intensities and a wide bandwidth, self-activated by a single-pulse laser. The experimental implementation will be an array of coupled microcavities realized as a spatially asymmetric nonlinear layered photonic structure several micrometers thick, optimized for operation in the visible range. In the linear regime (low input intensities), the system is simultaneously transparent to both forward and backward incidence, exhibiting high transmittance over a wide flat frequency band due to the spectral degeneracy of the reflectionless mode. The system switches to broadband reflection by breaking the PT symmetry of reflectionless modes by increasing the input intensity. Due to the inherent spatial asymmetry of the structure, the optical limiting threshold will be different for forward and backward propagation, resulting in unidirectional transmission over a wide range of incident light intensities. PT symmetry breaking will be caused by single-pulse light-induced changes in the refractive index in cavities using either the thermo-optical effect or the Kerr effect. The fabrication of the system will be outsourced, while the design and characterization will be done in the LENS laboratories of the Department of Physics of the University of Florence in Sesto Fiorentino (Florence, Italy).
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 05, 2025
- Source ID
- FA86552417007
Entities
People
- Tobias Kippenberg
Organizations
- Air Force Office of Scientific Research
- Swiss Federal Institute of Technology in Lausanne
- United States Air Force