LOQM — Quantum Photonics Research in India

LOQM is a quantum photonics research laboratory at IIT Bombay, India, led by Prof. Anshuman Kumar. As part of India’s National Quantum Mission, we build packaged quantum photonic sources — integrating atomically thin two-dimensional materials with nanofabricated optical cavities to generate single photons and high-dimensional qudits for real quantum communication and computation.

Quantum Photonics Research at IIT Bombay, India

Our experimental work spans four active research directions in quantum photonics India and beyond:

Quantum Single Photon Sources — We integrate two dimensional materials with photonic crystal cavities to engineer deterministic, high-brightness single photon emitters. Strain-induced localisation of excitons and defect centers create narrow-linewidth quantum emitters whose emission is enhanced via the Purcell effect. We characterise these sources using photon correlation measurements and Hong-Ou-Mandel interference. The goal is a fibre-coupled, packaged source ready for deployment in quantum networks and quantum key distribution systems.

Quantum Frequency Combs — We fabricate high-Q microring resonators that generate entangled photon pairs across many frequency bins via spontaneous four-wave mixing — an on-chip source of high-dimensional qudit states using the frequency degree of freedom of photons. Frequency-bin qudits are mutually orthogonal, individually addressable, and compatible with existing telecom fibre infrastructure, making them a practical route to scalable quantum communication networks in India and globally.

Topological Photonic Lattices — We design and fabricate photonic crystal lattices that support topologically protected edge states, then couple these to our single photon emitters to route quantum light immune to disorder and fabrication imperfections. Topological protection is especially valuable in the quantum regime, where even small losses can destroy fragile quantum states. We also probe non-Hermitian topology and exceptional points in these systems, connecting ideas from condensed matter physics to quantum photonics.

Photonic Machine Learning — We build Mach-Zehnder interferometer mesh networks, diffractive optical neural networks, and optical reservoir computers using 2D material nonlinearities — exploring both classical and quantum-enhanced photonic computation. Photonic neural networks perform matrix-vector multiplication at the speed of light, with orders-of-magnitude better energy efficiency than electronic processors. This project connects directly to our quantum photonics work, with the long-term goal of quantum-classical hybrid photonic computing.

Where We Are

Our laboratory is located in the Physics Department at IIT Bombay, Mumbai, India. We have full access to the nanofabrication facility for electron beam lithography, photolithography, and thin film deposition, alongside in-house quantum optical characterisation setups.

Our Research Impact

LOQM has published in leading international journals and our work has been covered widely in the scientific press. We collaborate with groups across India and internationally through the National Quantum Mission framework. Our students graduate with hands-on expertise in nanofabrication, quantum optics, and photonic device engineering — skills that are globally sought after in both academic and industry research.

Join Us

We recruit PhD students annually through the IIT Bombay Physics Department admissions process. Students with CSIR-JRF or UGC-JRF fellowships are encouraged to write directly to Prof. Kumar at anshuman@iitb.ac.in. Current openings are listed on our Openings page.