Prof. Anand Kumar Jha from the Department of Physics at IIT Kanpur and his team have developed an OAM (Orbital Angular Momentum) mode detector, recently published in Science Advances. This detector can measure OAM-mode spectrum of an unknown quantum state with remarkable precision. It is versatile, has uniform detection efficiency across a broad range of modes, and works equally well for both high-intensity and single-photon fields. The detector stands out for its fast measurement capabilities, completing measurements in minutes, and achieving over 98% fidelity even for 100-dimensional quantum states. This makes it a significant breakthrough in OAM detection of single-photon states.

The research, conducted at IIT Kanpur’s Quantum Optics and Entanglement lab, was performed by Prof. Anand Kumar Jha and his PhD student Suman Karan in collaboration with Prof. Martin van Exter of Leiden University who contributed a crucial piece of equipment. This new OAM detector is resistant to background noise, ensuring reliable performance in real-world conditions. It outperforms existing detection techniques in several performance parameters and can therefore have important consequences for OAM-based photonic quantum technologies, such as high--dimensional quantum cryptography, quantum communication and quantum imaging.

To read the full paper, visit: https://lnkd.in/eY6Y86Ff