In May I virtually attended CLEO. CLEO is one of the biggest conferences in the topic of laser science and photonics applications; it attracts researchers from all the world whose main area of research is photonics and light-matter interactions.

This year, CLEO consisted of 16 sessions in parallel multiple times per day from biophotonics to integrated circuits, from light sources to optical neural networks, from non-linear optics to ultrafast optics, etc. It was organised as a hybrid event. I found the topics of most of the sessions very interesting; they spanned from latest lasing to sensing technologies, and their exploitations in timely applications e.g. biomedical, gas sensing, and autonomous vehicles. A common goal of all of these research works was to achieve next generation photonics devices where all the photonics components are integrated on a chip. Because of their technology maturity and cost advantage, silicon photonics is largely used for such purposes, and in relation to this I found particularly inspiring the plenary talk by Dr Lipson entitled “The Revolution of Silicon Photonics”. The focus of the research presented was, however, not only limited to silicon; there were many contributions involving SiN, III-V semiconductors, lithium niobate, graphene, and superconductor technologies. The photon-matter interaction (from macroscale to nanoscales) and the propagation of photons through media was also the centre of many presentations; regarding the latter, the plenary talk by Dr Cao entitled “Seeing Through Walls and Around Corners: Shaping the Flow of Light in Complex Media” was of great interest. I found it very rewarding having our EBMs fully engaged with the conference, I have attended with great pleasure our EBM/GE Dr Lucia Caspani’s invited talk entitled “Generation and Characterization of Photonic Cluster States on-chip”.

Among the sessions that I attended, I would like to point out the following:

• Digital and dual comb metrology. I found the talk presented by Voumard et al. entitled “Dual-Comb Spectroscopy for Astronomical Spectrograph Calibration” remarkable, since it gave me further insights on how dual combs can be used in astronomical instrumentation.
• THz generation and application II. It is worth highlighting the study presented by Mansourzadeh et al. entitled “5.6 mW Average Power THz Source With 8 THz Bandwidth at 540 kHz Repetition Rate Based on Organic Crystal BNA”. I found fascinating the use of organic crystals for producing a such high-performance (ultra-broadband, high dynamic range) THz source.
• New Paths for Biosensing. A personal highlight is the invited talk given by Dr Zalevsky entitled “Photonic Medicine: New Paths in Remote Photonic bio-Sensing and Medical Diagnosis”. This presentation not only gave a laser-based bio-parameters sensing approach (based upon spatial analysis of time-changing back-scattered speckle patterns reflected from an inspected subject), but also showed the use of bio-parameters for doing medical diagnosis by applying machine learning post-processing. Other interesting works were those presented by Dr Altug’s group and Dr Su’s group.
• Advances in LIDAR for Physical and Atmospheric Sensing Applications. It is worth highlighting the work presented by Hamperl et al. entitled “Demonstration of Range-Resolved Detection of Stable Water Isotopologues by Differential Absorption Lidar”. I particularly appreciate this presentation since it gave me new insights in LIDAR and DIAL technologies, in particular seeing how to use them to achieve range-resolved measurements of stable water isotopologues H216O and HD16O in the lower troposphere.
• Photonics of Low Dimensional Materials and Nanostructures. Talks that generated a lot of questions are those presented by members of Nam’s group entitled “Engineering Carrier Dynamics in Pseudo-Landau-Quantized Graphene Towards Developing Graphene Lasers” and “Strongly Modified Broadband Ultrafast Photoluminescence at Telecom Wavelengths From CVD Monolayer Graphene”. Because of the zero-bandgap, the achievement of graphene lasers is challenging; it was very interesting to see how strong pseudo-magnetic fields in strained graphene significantly modifies the hot carrier dynamics, ultimately for next generation of graphene lasers.
• Single-Photon Detectors. A personal highlight is the invited talk given by Dr Lita entitled “Superconducting Photon-Number-Resolving Detectors Development and Applications”. I worked with single photons detectors, and I loved to see the latest advances in such topic; it was of great interest to look at the recent achievements in Transition-Edge Sensors superconducting single-photon detectors, in particular their intrinsic photon-number-resolving capability as well as their applications in quantum information. 
• Advances in Mid-Infrared Atmospheric Sensing. It is worth highlighting the invited talk given by Dr Kriesel entitled “Mid-IR Hollow Fiber gas Sensor Applications in Environmental Sensing and Isotope Analysis”. It was stimulating to see these novel compact sensors, which enable accurate trace gas and isotope analysis of greenhouse gases in the field.
• Quantum Dots & Color Centers. I found the invited talk given by Dr Simmons entitled “Silicon Colour Centres” particularly inspiring, it showed how newly rediscovered silicon colour centres, combining telecommunications-band optical transitions and long-lived spin qubits, can unlock matter-photon interfaces for silicon quantum networks.

For those interested, more information on the conference program can be found at:

2022-CLEO-Agenda-of-Sessions.pdf (cleoconference.org)