A5002206184- Spectroscopy and Laser Applications
- Atmospheric Ozone and Climate
- Atmospheric and Environmental Gas Dynamics
- Advanced Combustion Engine Technologies
- Combustion and flame dynamics
- Advanced Fiber Laser Technologies
- Laser Design and Applications
- Advanced Fiber Optic Sensors
- Advanced Chemical Sensor Technologies
- Photonic Crystal and Fiber Optics
- Atmospheric chemistry and aerosols
- Gas Sensing Nanomaterials and Sensors
- Photonic and Optical Devices
- Analytical Chemistry and Sensors
- Advanced Chemical Physics Studies
- Combustion and Detonation Processes
- Catalytic Processes in Materials Science
- Heat transfer and supercritical fluids
- Radiation Dose and Imaging
- Medical Imaging Techniques and Applications
- Advanced X-ray and CT Imaging
- Advanced Sensor Technologies Research
- Chemical Thermodynamics and Molecular Structure
- Spectroscopy and Chemometric Analyses
- Catalysis and Oxidation Reactions
Chinese University of Hong Kong
2016-2025
Chinese University of Hong Kong, Shenzhen
2017-2025
Southern Medical University Shenzhen Hospital
2025
Southern Medical University
2025
Prince of Wales Hospital
2023
Beijing University of Posts and Telecommunications
2006-2021
City University of Hong Kong, Shenzhen Research Institute
2018-2020
Government of Northwest Territories
2018-2020
National Institute of Standards and Technology
2018-2019
Physical Measurement Laboratory
2018-2019
MOF-based nanofiber filters <italic>via</italic> a scalable synthetic strategy serve dual role in removing both PM<sub>2.5</sub> and formaldehyde effectively.
Sensors are perhaps the most important and integral components of our modern society. With global warming environmental pollution garnering ever-increasing attention, as well solutions for sustainabile smart cities, optimized performance current future energy systems process industries is paramount. The accurate sensing quantification key parameters such essential monitoring, controlling, optimization efforts. In situ laser-based optical sensors suitable achieving desired characteristics...
Photoacoustic spectroscopy (PAS) based gas sensors with high sensitivity, wide dynamic range, low cost, and small footprint are desirable in energy, environment, safety, public health. However, most works have focused on either acoustic resonator to enhance wave or optical wave. Herein, we develop a sensor doubly resonant PAS which the waves simultaneously enhanced using combined resonators centimeter-long configuration. Not only lower detection limit is by double standing waves, but also...
Abstract Dual-comb spectroscopy (DCS) has revolutionized optical by providing broadband spectral measurements with unprecedented resolution and fast response. Photothermal (PTS) a pump-probe configuration offers highly sensitive gas sensing method, which is normally performed using single-wavelength pump laser. The merging of PTS DCS may enable spectroscopic method taking advantage both technologies, never been studied yet. Here, we report dual-comb photothermal (DC-PTS) passing dual combs...
Abstract Photoacoustic dual-comb spectroscopy (DCS), converting spectral information in the optical frequency domain to audio via multi-heterodyne beating, enables background-free measurements with high resolution and broad bandwidth. However, detection sensitivity remains limited due low power of individual comb lines lack broadband acoustic resonators. Here, we develop cavity-enhanced photoacoustic DCS, which overcomes these limitations by using a high-finesse cavity for amplification...
Near-to-mid-infrared photodetection technologies could be widely deployed to advance the infrastructures of surveillance, environmental monitoring, and manufacturing, if detection devices are low-cost, in compact format, with high performance. For such application requirements, colloidal quantum dot (QD) based photodetectors stand out as particularly promising due solution processability ease integration silicon technologies; unfortunately, detectivity QD toward longer wavelengths has so far...
In this Letter, a sensitive light-induced thermoelastic spectroscopy (LITES)-based trace gas sensor by exploiting super tiny quartz tuning fork (QTF) was demonstrated. The prong length and width of QTF are 3500 µm 90 µm, respectively, which determines resonant frequency 6.5 kHz. low is beneficial to increase the energy accumulation time in LITES sensor. geometric dimension on micrometer scale advantageous obtain great thermal expansion thus can produce strong piezoelectric signal....
A methane (CH4) and nitrous oxide (N2O) sensor based on a sensitive, selective well established technique of quartz enhanced photoacoustic spectroscopy (QEPAS) was developed for environmental biomedical measurements. thermoelectrically cooled (TEC) distributed feedback quantum cascade laser (DFB-QCL), capable continuous wave (CW) mode hop free emission in the 7.83 μm wavelength range, used as an excitation source. For targeted CH4 N2O absorption lines located at 1275.04 cm−1 1275.49...
Abstract An IR laser absorption diagnostic has been further developed for accurate and sensitive time‐resolved measurements of ethylene in shock tube kinetic experiments. The utilizes the P14 line a tunable CO 2 gas at 10.532 μm (the (0 0 1) → (1 0) vibrational band) achieves improved signal‐to‐noise ratio by using photovoltaic detectors identification via an MIR wavemeter. Ethylene cross sections were measured over 643–1959 K 0.3–18.6 atm behind both incident reflected waves, showing...
We demonstrate the first, to best of our knowledge, photothermal carbon monoxide (CO) sensor using a hollow-core negative curvature fiber. The fiber features typical structure one ring cladding containing eight nontouching capillaries form core-surround. effect in 40-μm hollow core is induced by CO absorption at 2327 nm and detected Mach-Zehnder interferometer operating 1533 nm. By wavelength modulation spectroscopy, we achieve normalized noise equivalent coefficient 4.4×10-8 cm-1 WHz-1/2....
Reliable hydrogen (H2) detection is essential for advancing energy applications. In this study, we report a sensitive H2 method using off-axis integrated cavity output spectroscopy. A distributed-feedback laser with fiber was used to target the absorption transition near 2122 nm. The optical constructed two spherical mirrors, each reflectivity of 99.985%, providing an effective path length 2500 m. Galatry line shape function selected accurately fit narrow feature H2. Furthermore, achieved...
A quartz-enhanced photoacoustic absorption spectroscopy (QEPAS)-based gas sensor was developed for methane (CH₄) and nitrous-oxide (N₂O) detection. The QEPAS-based installed in a mobile laboratory operated by Aerodyne Research, Inc. to perform atmospheric CH₄ N₂O detection around two urban waste-disposal sites located the northeastern part of Greater Houston area, during DISCOVER-AQ, NASA Earth Venture September 2013. continuous wave, thermoelectrically cooled, 158 mW distributed feedback...
Quartz-enhanced photoacoustic spectroscopy (QEPAS) based on double acoustic microresonators (AmRs) is developed and experimentally investigated. The AmR spectrophone configuration exhibits a strong coupling between the quartz tuning fork, which results in ∼5 ms fast response time. Moreover, AmRs provide two independent detection channels that allow optical signal addition or cancellation from different wavelengths facilitate rapid multigas sensing measurements, thereby avoiding laser beam...
A quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor has been developed for the sensitive detection of ethylene (C2H4) at 10.5 µm using a continuous-wave distributed-feedback quantum cascade laser. At this long-wavelength infrared, key acoustic elements quartz tuning fork and micro-resonators were optimized to improve signal-to-noise ratio by factor >4. The calibration demonstrated an excellent linear response (R2>0.999) C2H4 concentration selected operating pressure 500 760 Torr....
We demonstrate an ultrasensitive photoacoustic sensor using a low laser power (4 mW) and high-finesse (>9000) optical cavity. The Pound-Drever-Hall (PDH) method is adopted to lock the external cavity diode at 1531.58 nm Fabry-Pérot By placing cell inside 130-mm-long cavity, we obtain enhancement of more than 630 times in for acetylene (C2H2) detection. present spectroscopy (PAS) achieves normalized noise equivalent absorption coefficient 1.1×10-11 cm-1 WHz-1/2, which unprecedented...