December 12, 2024 — A nano-sized on-chip device that produces high-quality light with over 93% polarization purity at room temperature, has been developed by Hebrew University researchers.

The research, published in ACS Photonics, details how they produced radially polarized light, that is useful for a range of applications, including secure and quantum communication, advanced imaging, and precision optics. Until now, producing this level of light reliably, especially in nano-photonic systems, has been a technical challenge.

Researchers addressed this challenge by combining a “giant” CdSe/CdS colloidal nanocrystal quantum dot (20 nm) with a hybrid metal-dielectric nanoantenna. The quantum dot is precisely placed on a tiny metal nanocone at the antenna center, which allows the device to generate photons with over 93% radial polarization purity.

“The accurate positioning of the quantum dot plays a key role in achieving high-quality light output,” said Prof. Ronen Rapaport of the Hebrew University Racah School of Physics. “This study helps us better understand how to control light polarization in small-scale devices, which is important for future quantum applications.”

The research paper, titled “Ultrafast and Highly Collimated Radially Polarized Photons at Room Temperature from a Colloidal Quantum Dot Coupled to a Hybrid Nanoantenna” is now available in ACS Photonics and can be accessed here.

 Researchers:

Alexander Nazarov¹, Yuval Bloom¹, Boaz Lubotzky¹, Hamza Abudayyeh², Annika Mildner³, Lorenzo Baldessarini⁴, Yuval Shemla¹, Eric G. Bowes⁵, Monika Fleischer , Jennifer A. Hollingsworth⁵, Ronen Rapaport¹

Institutions:

1. Racah Institute of Physics, Hebrew University of Jerusalem
2. Department of Physics, University of Texas at Austin
3. Institute for Applied Physics and Center LISA, University of Tuebingen
4. Department of Physics, Trento University
5. Materials Physics & Applications Division: Center for Integrated Nanotechnologies