Ozone Detection via Deep-Ultraviolet Cavity-Enhanced Absorption Spectroscopy with a Laser Driven Light Source

Area of Science:

• Atmospheric Chemistry
• Spectroscopy
• Sensor Technology

Background:

• Ozone is a key air pollutant with significant health and environmental impacts.
• Accurate and real-time ozone monitoring is crucial for environmental and health studies.
• Existing ozone detection methods have limitations in terms of accuracy, response time, or portability.

Purpose of the Study:

• To develop and validate a novel sensing approach for ambient ozone detection.
• To utilize deep-ultraviolet (DUV) cavity-enhanced absorption spectroscopy (CEAS) with a laser driven light source (LDLS).
• To assess the sensor's accuracy, precision, response time, and applicability for real-world air sampling.

Main Methods:

• Employing DUV-CEAS with an LDLS emitting between ~230-280 nm.
• Utilizing an optical cavity with high-reflectivity mirrors to achieve an effective path length of ~58 m.
• Detecting CEAS signals with a UV spectrometer and fitting spectra to determine ozone concentration.

Main Results:

• Achieved high sensor accuracy (<~2% error) and precision (~0.3 ppb at ~5 s measurement time).
• Demonstrated a fast sensor response time (10-90% response of ~0.5 s) due to a small optical cavity volume (<~0.1 L).
• Showed favorable agreement with a reference analyzer during outdoor air sampling.

Conclusions:

• The DUV-CEAS sensor provides a highly accurate, precise, and fast method for ambient ozone detection.
• Its compact design and performance make it suitable for ground-level and mobile air quality monitoring.
• The DUV-CEAS-LDLS approach shows potential for detecting other ambient gases, including volatile organic compounds.