Grantee Research Project Results
2000 Progress Report: Development of All-Solid-State Sensors for Measurement of Nitric Oxide and Carbon Monoxide Concentrations by Optical Absorption
EPA Grant Number: R828180Title: Development of All-Solid-State Sensors for Measurement of Nitric Oxide and Carbon Monoxide Concentrations by Optical Absorption
Investigators: Walther, Thomas , Caton, Jerry , Lucht, Robert P.
Institution: Texas A & M University
EPA Project Officer: Hahn, Intaek
Project Period: July 1, 2000 through June 30, 2002
Project Period Covered by this Report: July 1, 2000 through June 30, 2001
Project Amount: $225,000
RFA: Exploratory Research - Engineering, Chemistry, and Physics) (1999) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Water , Air , Safer Chemicals , Land and Waste Management
Objective:
The objective of this research is the development of new optical sensors for the detection of nitric oxide (NO) and carbon monoxide (CO) in the exhaust streams of combustion systems. Sensors based on absorption measurements combine high sensitivity and real-time capabilities. Present sensors rely on physical sampling techniques that are inherently slow.The specific objectives of this research are to: (1) develop a fiber-amplified, diode laser based UV optical sensor for NO measurements and mid-infrared sensor for CO measurements; (2) characterize the performance of the sensors by absorption measurements in a gas cell, simulated combustion exhaust streams, and a well-characterized flame, and compare with Fourier Transform Infrared (FTIR) measurements and probe sampling; and (3) complete a feasibility study of the incorporation of the sensor systems in practical systems for pollutant monitoring and control.
Progress Summary:
All important system components for the NO sensor are in place. We have purchased and installed several crucial electronic components for monitoring the operation of the sensor, including a digital lock-in amplifier and a high-finesse Fabry-Perot spectrum analyzer. The generation of 266-nm light using the Nd-doped fiber amplifier, PPLN crystal, and BBO crystal has been demonstrated in our OH sensor. The external cavity diode laser at 1535 nm is available. Work on the Er:doped fiber amplifier will start shortly.
We also have made significant progress on the development of stabilized cavities for efficient frequency-doubling and sum frequency generation. We have observed resonant cavity enhancement of the frequency doubling of 532-nm radiation. Currently, the work on the electronics to stabilize the cavity length by feedback control of a piezo-driven prism in the cavity is almost completed.
For the CO sensor we will produce the necessary radiation at 4.5 micron by difference frequency mixing of 860-nm and 1064-nm light. Most components for the CO sensor have arrived. In particular, we have received the external cavity diode laser at 860 nm, the periodically poled LiNbO3 crystal, which will be used for difference frequency mixing of the 860-nm and 1064-nm radiation to produce the 4.5 micron radiation. The InSb-detectors for the detection of the mid-infrared radiation have been ordered. They are expected to be delivered shortly.
While waiting for various components for the NO and CO sensors and to prove the feasibility of our sensor concepts as quickly as possible, we have demonstrated an OH sensor. The experience with this system has led to significant improvements in the design of the NO sensor.
Future Activities:
The next steps we are planning are: (1) completion of the build-up cavities; (2) implementation of the difference frequency mixing for the CO sensor; (3) absorption measurements of CO in a gas cell; and (4) implementation of a second generation 1064-nm fiber amplifier system with major improvements.Journal Articles on this Report : 1 Displayed | Download in RIS Format
| Other project views: | All 13 publications | 2 publications in selected types | All 2 journal articles |
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Ray GJ, Anderson TN, Caton JA, Lucht RP, Walther T. OH sensor based on ultraviolet, continuous-wave absorption spectroscopy utilizing a frequency-quadrupled, fiber-amplified external-cavity diode laser. Optics Letters 2001;26(23):1870-1872. |
R828180 (2000) R828180 (2002) R828180 (Final) |
not available |
Supplemental Keywords:
pollutant monitor, pollutant emissions, diode lasers, optical sensors, nitric oxide, carbon monoxide, fiber amplifiers., RFA, Air, Scientific Discipline, Waste, Toxics, HAPS, Environmental Chemistry, Engineering, Chemistry, & Physics, Incineration/Combustion, tropospheric ozone, EPCRA, Physics, Environmental Monitoring, nitrous oxide, air sampling, combustion systems, pollutant monitoring, fiber ampiliers, risk assessment, measurement methods , nitric oxide (NO), chemical detection techniques, combustion, carbon monoxide, optical absorption, smog, ambient emissions, diode laser, Nitric oxide, probe sampling, air quality standards, laser based optical sensor, Fourier Transform Infrared measurement, diode laser spectrometerRelevant Websites:
http://faculty.physics.tamu.edu/walther Exit
http://people.tamu.edu/~s0r5220/home.html Exit
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.