About State Key Laboratory of Precision Spectroscopy

State Key Laboratory of Precision Spectroscopy

The State Key Laboratory of Precision Spectroscopy, known by the abbreviation SKLPS, is a national research laboratory managed by East China Normal University in Shanghai. It is a member of the national laboratory system supported by the Ministry of Science and Technology of the People's Republic of China, and it is devoted to spectroscopy and measurement at the limits of sensitivity, resolution and precision. Located on the university's downtown campus at 3663 North Zhongshan Road, the laboratory builds on more than sixty years of optics research at East China Normal University, a field in which the university claims distinctive advantages in optical spectroscopy with high resolution, high precision and high sensitivity.

History: From Quantum Optics to a State Key Laboratory

The laboratory was founded in 1986. In 1990 it received the name Open Research Laboratory of Quantum Optics from the Ministry of Education. Over the following decade it established itself as the Key Laboratory of Optical and Magnetic Resonance Spectroscopy of the Ministry of Education. It joined National Project 211 and became part of a Project 985 science and technology innovation platform in 2006. In January 2007 it was authorised as a state key laboratory by the Ministry of Science and Technology. This staged progression — from a university laboratory founded in the mid-1980s, through ministry open and key laboratory status, to full state key laboratory status in 2007 — is typical of China's laboratory system, in which institutions earn national status through successive evaluations over many years.

The laboratory's older accounts describe premises covering about 4,000 square metres of experimental rooms together with about 2,500 square metres of offices on the downtown campus; its current official introduction describes a larger footprint of 15,000 square metres of experimental rooms and 5,000 square metres of offices, reflecting its growth. Its leadership pages record an executive director, E Wu, in recent listings, and an academic and steering structure drawing on senior figures in Chinese optics including Jian Wu, Heping Zeng and Ya Cheng among the members of its academic committee.

Mission and Overall Character

The laboratory describes itself as having developed into a comprehensive scientific research institute with modern optics as its leading orientation. Its stated focal points are the exploration of significant fundamental science frontiers, the development of large engineering techniques and pioneering laser and optoelectronic applications, with high-technology innovation and basic research for application as its core mission. In its own formulation, it aims primarily at research in spectroscopy with high sensitivity, high resolution and high precision — the three qualities that give precision spectroscopy its name and define its experimental culture.

Precision spectroscopy is the measurement of the frequencies, intensities and shapes of spectral lines — the light absorbed or emitted by atoms and molecules — with the greatest attainable accuracy. Because spectral lines are determined by the internal structure of atoms and molecules and by the fundamental constants of physics, measuring them precisely serves several purposes at once: it tests fundamental theory, it provides the references on which optical clocks and precision measurement instruments are built, it identifies and quantifies substances at extremely low concentrations, and it follows chemical and physical processes on the fastest timescales. The laboratory's programme is organised to pursue all of these purposes together.

Research Directions

East China Normal University's official summary organises the laboratory's work into three research directions: precision spectroscopy in the time-frequency domain; ultra-sensitive precision spectroscopy; and micro- and nano-scale precision spectroscopy. Earlier laboratory descriptions identified five cornerstone areas of competence serving as the backbone of its projects, including precision spectroscopy by optical field control in the time and frequency domain, and precision spectroscopy of atoms and molecules. These formulations overlap: all of them divide the field by how precision is achieved — by controlling light fields in time and frequency, by pushing detection sensitivity to the level of very few photons or molecules, and by confining spectroscopy to microscopic and nanoscopic systems.

The laboratory's experimental platforms, as listed by the university, give concrete form to those directions. They comprise ultracold quantum systems for precision measurement and manipulation; ultrafast physical property precision measurement and manipulation; advanced manufacturing beyond the limit with ultrafast lasers; optical field time-frequency domain precision control; optical clock physics and ultra-sensitive measurement and application; and micronano photonics and devices. Together the six platforms span the laboratory's range from fundamental quantum systems to laser manufacturing technology.

Time-Frequency Precision, Optical Clocks and Ultracold Systems

Time-frequency domain precision spectroscopy uses the tools of modern laser physics — frequency combs, ultrastable lasers and precise phase control — to measure optical frequencies, which oscillate hundreds of trillions of times per second, against the standards that define time itself. Optical clocks, which count an optical transition in an atom or ion rather than the microwave transition used in caesium clocks, are the most demanding application of this work, offering the prospect of timekeeping and frequency standards far more precise than current definitions allow, with consequences for navigation, communications networks, geodesy and tests of fundamental physics. The laboratory maintains a dedicated platform for optical clock physics and ultra-sensitive measurement and application, and a platform for ultracold quantum systems, in which atoms cooled to near absolute zero provide exceptionally well-controlled subjects for precision measurement and quantum manipulation.

Ultrafast Measurement and Attosecond Science

At the opposite end of the timescale, the laboratory works on ultrafast measurement. Its profile identifies ultrafast measurement and attosecond science among its activities, supported by its platform for ultrafast physical property precision measurement and manipulation and its platform for advanced manufacturing beyond the limit with ultrafast lasers. Attosecond science — the study and use of light pulses lasting billionths of a billionth of a second — allows researchers to follow electron motion in atoms and molecules on its natural timescale. Ultrafast lasers are also industrial tools: focused ultrashort pulses can machine and structure materials with minimal thermal damage, which is why advanced manufacturing with ultrafast lasers appears as a platform in its own right in a laboratory otherwise devoted to measurement.

Ultra-Sensitive Detection and Single-Photon Work

Ultra-sensitive precision spectroscopy seeks to detect and measure the weakest possible signals. A representative line of work from the laboratory is the infrared photon measurement research of Heping Zeng's team. In work published in Nature Communications, Zeng and Kun Huang's group reported wide-field mid-infrared single-photon upconversion imaging, using a chirped periodically poled lithium niobate crystal to achieve adaptive phase matching for signals arriving at different angles, obtaining a reception angle at least an order of magnitude larger than traditional schemes and achieving mid-infrared imaging at the single-photon level under extremely low illumination. The mid-infrared band is the molecular fingerprint region, containing the characteristic absorption signatures of many molecules, and it also covers atmospheric transmission windows; ultra-sensitive detection there supports molecular spectroscopy, astronomical observation, environmental remote sensing and biomedical diagnosis. The same group has pursued a series of results in infrared photon measurement and control, including ultrasensitive silicon-based infrared detection, illustrating how the laboratory converts nonlinear optics techniques into measurement capabilities.

People and Training

The university records that the laboratory has more than ninety permanent members, among them fifty-four professors and nineteen associate professors, with about seventy per cent below the age of forty-five, and that more than three hundred master's and doctoral students are learning there. That age structure — a large senior faculty combined with a predominantly young permanent staff and a student body more than three times the size of the faculty — is characteristic of a major Chinese state key laboratory, which functions simultaneously as a research institute and as one of its university's principal graduate training bases. The laboratory recruits internationally, advertising faculty positions to candidates eligible for national young talent programmes as well as university talent schemes and postdoctoral posts.

Recognition and Scientific Standing

University accounts of the laboratory record that its research results have been quoted three times in Nobel Prize speeches, a distinction it attributes to three generations of effort that have earned it a reputation for high resolution, high sensitivity and high accuracy. In October of the year recorded in the university's report, Nobel laureate Chen-Ning Yang visited the laboratory, where a Chen-Ning Yang Studio was established in his name, intended to promote academic cooperation and the development of physics at the university; Yang inscribed his pleasure at seeing the university shifting focus to science, and his disciple Zhang Shoucheng, who accompanied him, inscribed the hope that the studio would become a magnet for global talents. Such visits mark the laboratory's standing within Chinese physics, while its day-to-day standing rests on its publication and measurement record in laser spectroscopy, quantum optics and precision measurement.

Place within East China Normal University

East China Normal University, founded in Shanghai in October 1951, is sponsored by the national Project 211, Project 985 and Double First-Class programmes, and operates campuses in Putuo and Minhang districts. The State Key Laboratory of Precision Spectroscopy is one of its two state key laboratories, alongside the State Key Laboratory of Estuarine and Coastal Research, and it anchors the university's strength in physics, where its departments hold established positions in optics, atomic and molecular physics, condensed matter physics and theoretical physics. For a university historically renowned for teacher education and the humanities, the laboratory represents its flagship in the physical sciences — the institutional form of its six-decade investment in optics.

Outlook

The laboratory's programme points toward the continuing convergence of spectroscopy, quantum technology and precision measurement. Optical clocks and ultracold quantum systems connect it to quantum information and metrology; attosecond and ultrafast platforms connect it to the fastest processes in matter and to laser manufacturing; ultra-sensitive and single-photon methods connect it to sensing problems from pollution monitoring to disease diagnosis; and micro- and nano-photonics connect it to integrated devices. Its founding commitment — spectroscopy at the highest attainable sensitivity, resolution and precision — remains the thread through all of these directions, pursued from its base at 3663 North Zhongshan Road in Shanghai as part of China's national laboratory system.