Course Title: Single Photon Generation, Detection, and Applications

Course Level: Advanced Beginner, Intermediate 

Course Description:

Quantum information applications in optical domain require the control of the optical field at a single photon level. This course covers single-photon, entanglement, other non-classical light sources, single-photon detectors, and their practical use. 

The single-photon technology is truly interdisciplinary and covers multiple fields, including optics, electronics, and fundamental physics. Because faint light occurs in diverse practical settings, from fundamental physics to remote sensing and biology, new measurement methods for these light-emitting systems can be developed based on light characterization, and often by merely counting emitted photons. In addition, we will discuss the use of single-photons and entangled states for quantum networks. 

We will talk about different methods to generate single photon light and other nonclassical states, including entangled states. Deterministic sources are based on single quantum emitters such as a single atom, a single molecule, or a quantum dot. Probabilistic sources use optical nonlinearities and rely on parametric down-conversion and four-wave mixing. Yet, quantum memory-based sources may combine the probabilistic excitation with deterministic single photon emission. 

We will review the characteristics of the ideal single photon state and learn how to characterize the state via a measurement. Traditionally, second-order correlation functions are used for characterization. Other methods may enhance our understanding of the state. We will discuss practical examples where properties of the light field and even underlying physics of light emitters are uncovered via those measurements. 

There exists a variety of single-photon detectors, from photomultiplier tubes to avalanche photodiodes and superconducting sensors. Detectors, due to their complexity, cannot be simply described by detection efficiency. Other parameters, such as deadtime and afterpulsing, play an important role. 

Single photons are a natural choice for quantum communication. Indeed, photons do not readily interact with atoms in transparent media. We will review basic quantum communication protocols, such as quantum key distribution, entanglement swapping, and quantum teleportation and their implementation in photonic networks. 

Benefits and Learning Objectives: 

This course is designed as an introduction to practical quantum optics and should help participants to obtain basic working knowledge that enables their entry into the field. Specifically,  

• Recognize the benefit of single-photon sources and detectors for your own research. Find ideas to enhance their application(s). 

• Become knowledgeable of present and future trends in single-photon research and quantum optics and identify own strategic goals in this field. 

• Learn properties of single-photon sources and detectors. 

• Obtain basic knowledge on components for photonic quantum information applications and quantum networks.  

• Develop a photon-counting-based application on a conceptual level.  

• Learn the proper way to understand measurement results with faint light states.  

• Learn key statistical methods relevant to faint light measurement and characterization. 

 

Intended Audience:

Graduate students, post-docs, faculty, researchers, and technical personnel in academia, industry, and government labs looking for an introduction in practical quantum optics and single-photon technology.  

The only requirement to comprehend and benefit from the course is an undergraduate course in physics/ applied physics/electrical engineering covering the basics of optics. An undergraduate course on quantum mechanics would be helpful, but optional. The information presented in this short course should also be useful to patent attorneys and legal professionals who are active in a single photon technology area. 

Instructor Biography: 

Dr. Sergey V. Polyakov is Chief of the Quantum Measurement division, Physical Measurement Laboratory at NIST. He oversees a large set of efforts aimed at providing physical foundation for the SI system of units. Those projects span from fundamental efforts in quantum measurement to practical realization and dissemination of fundamental constants and units of measurement. His research experience is centered at developing quantum methods of characterization of faint light with applications ranging from classical and quantum networking to quantum-enabled biophotonics. Sergey contributed to early research efforts in quantum repeaters. He developed innovative methods of single photon source characterization that leads to in-situ, non-invasive measurement of underlying physics of single-photon emitters. Recently, he invented and developed a new class of optical receivers for classical communications that use quantum measurement. He performed one of the most accurate single photon detector characterizations.  Sergey is a Fellow of the Optical Society of America and has served as a General Chair of CLEO conference (2021), and Nonlinear Photonics topical meeting (2022).