Work

Dipole orientation-dependent Purcell enhancement in silicon nitride dielectric waveguides using isotropic quantum dots and anisotropic nanoplatelets

Year: 2026

Type: article

Abstract: We investigate the modification of spontaneous emission from quantum emitters positioned in the near field of silicon nitride dielectric waveguides. The role of dipole orientation is investigated through combined numerical simulations and experimental measurements by resolving normal, tangential, and parallel dipole components relative to the waveguide surface. The simulations reveal that emission enhancement depends strongly on the vectorial overlap between the emitter dipole and the guided-mode field components. Spherical quantum dots, exhibiting nearly isotropic dipole orientations with significant normal components, show higher ensemble-averaged Purcell enhancement, while anisotropic nanoplatelets, with predominantly in-plane dipole moments, display comparatively lower enhancement due to restricted coupling to the normal field component. Photoluminescence measurements and time-resolved studies are consistent with these trends, indicating orientation-dependent, cavity-free Purcell enhancement in integrated dielectric waveguides and establishing a qualitative framework for evaluating emitter orientation effects in waveguide-based quantum photonic platforms.

Source: Journal of Applied Physics

DOI: 10.1063/5.0333343

Authors: Sushma Gali, Komal Sharma, Jaydeep Kumar Basu, Shankar Kumar Selvaraja

Institution: Indian Institute of Science Bangalore

Language: English

Topic: Photonic and Optical Devices

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,500

Funders: Indian Institute of Science, Department of Science and Technology, Ministry of Science and Technology, India, University Grants Commission, National NanoFab Center