Upcoming Talks

The remarkable optical characteristics of diamond, along with its various intrinsic color centers that possess long coherence times, have fostered a vibrant and expanding research community in recent decades. Diamond-based integrated photonic circuits (PIC) are increasingly contributing to advancements in quantum sensing, computing, and communication technologies. Although significant strides have been made in device fabrication demonstrations, challenges related to reproducibility and scalability persist. We investigate the development of lateral wave guide structures on diverse diamond substrates, with an emphasis on the integration of color centers such as the Nitrogen Vacancy (NV) and Silicon Vacancy (SiV) defects. We carried out electric field simulations to optimize device performance. Optical microring resonators, waveguides, and photonic crystal cavities were processed employing electron-beam lithography, metal/dielectric mask deposition, and oxygen dry etching via “Inductively coupled plasma” (ICP). Undercutting was accomplished with means of Faraday-Cage-Angled-Etching (FCAE) as well as quasi-isotropic etching, and we evaluate the pros and cons of these techniques. The devices were analyzed using micro-photoluminescence, revealing resonant cavity modes within the large phonon sidebands of the NV emission spectrum. Furthermore, hetero integration of the photonic integrated circuits was tested with the aid of micromanipulators.

Dr. Christian Giese studied physics at the university of Freiburg where he acquired his P.h.D. working of quantum optics and atomic physics in 2012. He then started his career at Zeiss SMT Oberkochen focusing on metrology of EUV optics for next generation EUV steppers. In 2013 he joined the technology department at the Fraunhofer IAF in Freiburg to develop cleanroom processes for diamond based devices. He holds a number of patents, is author or co-author of more than 40 peer-reviewed publications and leads the nanofabrication technology activities for NV-devices at IAF. Research interests: semiconductor technology development, electron beam lithography, laser ligthography, dry etching, diamond devices, color centres, optical metrology, photonic integrated circuits, quantum technology

Nanoscale quantum optics shows great promise as a platform for future quantum information applications, owing to its compact dimensions, enhanced light-matter interactions, and compatibility with current on-chip technologies. In such nanoplatforms, single photons can carry quantum information in various physical degrees of freedoms such as position, propagation direction, time slot, frequency, energy, orbital angular momentum, and spin. In macroscopic settings, the spin and orbital angular momentum of light are separable, hence can be utilized as separate degrees of freedom present entanglement between them [1]. But in nanophotonic platforms the electromagnetic waves are strongly confined, hence the spin and orbital angular momentum of light become inseparable, leaving only the total angular momentum of the confined modes as a good quantum number. This talk will present our studies on photons entangled in their total angular momentum in a nanophotonic platform [2], where the spin and orbital angular momentum of light are inseparable. On the fundamental side, we unravel the evolution of quantum information in heralded single photons as they couple into- and out of- the near-field of a nanophotonic system. We find that the qubit encoded in total angular momentum of the near-field photons becomes a free-space qudit entangled in the photonic spin and orbital angular momentum degrees of freedom. Finally, the talk will touch upon some of our newer projects, dealing with encoding quantum information in quantum skyrmions [3] and plasmonic lattices which expand the Hilbert space into hyper-entangled states [4]. [1] Stav, Tomer, et al. "Quantum entanglement of the spin and orbital angular momentum of photons using metamaterials." Science 361.6407 (2018): 1101-1104. [2] Kam, Amit, et al. "Near-field photon entanglement in total angular momentum." Nature 640.8059 (2025): 634-640. [3] Kam, Amit, et al. "Quantum skyrmions and high dimensional entanglement mediated by nanophotonics." To appear in eLight. https://doi.org/10.1186/s43593-026-00124-1 [4] Fridman, Lior, et al. "Hyperentanglement in Nanophotonic Systems with Discrete Rotational Symmetry." arXiv preprint arXiv:2511.00860 (2025). To appear in Nanophotonics.

Amit Kam is a Ph.D. student in Physics at the Technion - Israel Institute of Technology, where he conducts research on quantum nanophotonics and structured light under the supervision of Prof. Guy Bartal. He holds both a B.Sc. and an M.Sc. in Physics from the Technion.