Amorphous metal oxide mixtures for high-Q integrated nonlinear photonics

Area of Science:

• Integrated photonics
• Materials science
• Nonlinear optics

Background:

• Material choice is key in integrated photonics, but composition tuning is rare.
• Phase matching and thin-film deposition limit material options for nonlinear photonics.

Purpose of the Study:

• Explore amorphous titania (TiO2) and tantala (Ta2O5) mixtures for enhanced photonics.
• Investigate composition as a design parameter for tunable material properties.

Main Methods:

• Deposited ultralow-loss titania-tantala films using ion-beam sputtering at room temperature.
• Nanopatterned films to create microresonator frequency combs.

Main Results:

• Titania inclusion reduced oxygen-defect density in tantala films, maintaining high nonlinear index.
• Achieved microresonator quality factor up to 10^7 with a 1.7x reduction in optical absorption.
• Demonstrated lower loss, higher refractive index, and reduced optical absorption/photorefractive effects.

Conclusions:

• Titania-tantala is a promising material for integrated nonlinear photonics due to its tunable properties, low loss, and high nonlinearity.
• Material composition offers a new design parameter for integrated nonlinear photonics, alongside fabrication and device design.