Stable isotopic analysis of atmospheric methane by infrared spectroscopy by use of diode laser difference-frequency generation.
نویسندگان
چکیده
An infrared absorption spectrometer has been constructed to measure the stable isotopic composition of atmospheric methane samples. The spectrometer employs periodically poled lithium niobate to generate 15 microW of tunable difference-frequency radiation from two near-infrared diode lasers that probe the nu3 rotational-vibrational band of methane at 3.4 microm. To enhance the signal, methane is extracted from 25 l of air by use of a cryogenic chromatographic column and is expanded into the multipass cell for analysis. A measurement precision of 12 per thousand is demonstrated for both delta13C and deltaD.
منابع مشابه
Tunable Far Infrared Laser Spectroscopy
using C02 laser difference generation in metal-insulator-metal diodes either from the difference between a fixed frequency C02 laser and a tunable waveguide laser, or from the difference between two fixed frequency C02 lasers plus microwave sidebands. is being used to make highly accurate FIR frequency measurements of stable species to serve as frequency and wavelength calibration standards; to...
متن کاملCompact laser difference-frequency spectrometer for multicomponent trace gas detection
Design, performance characteristics, and application of a room temperature mid-infrared laser spectrometer are reported. This compact instrument is based on differencefrequency mixing of a widely tunable external-cavity diode laser and a diode-pumped monolithic Nd:YAG ring laser in periodically poled lithium niobate (PPLN). The differencefrequency tuning range of 3.98 μm to 4.62 μm was sufficie...
متن کاملMid-infrared difference-frequency generation in periodically poled KTiOAsO(4) and application to gas sensing.
Tunable mid-infrared radiation (3.45-3.75 microm) with a power level of 0.14 microW is generated by quasi-phase-matched difference-frequency mixing of a Nd:YAG laser and a tunable-diode laser (near 1.5 microm) in multigrating periodically poled KTiOAsO(4) . The wavelength and temperature bandwidths are approximately 65 nm cm and approximately 62 degrees C, respectively. The temperature-tuning s...
متن کاملTuning extension of a Difference-Frequency generation up to 100 nm using V-shaped external-cavity for the pump laser
In this research, tunability of a commercial diode laser has extended to about more than ± 11 nm using a V-shaped external-cavity fabricated around the laser. Although under normal condition it can be tuned up to about ± 4 nm just by changing its temperature and injection current. Such modified diode laser has then used in a difference-frequency generation (DFG) experimental setup as pump sourc...
متن کاملContinuous-Wave Difference-Frequency Generation in Periodically Poled RbTiOAsO4 Crystal and Application to Isotopic Analysis of Methane
We report on development of a widely tunable infrared (3.4-4.5 μm) continuous-wave laser spectrometer based on difference frequency generation in a periodically poled RbTiOAsO4 crystal and its application to isotope analysis of CH4/CH4. ©2006 Optical Society of America OCIS codes: (190.2620) Frequency conversion; (190.4400) Nonlinear optics, material; (300.6360) Laser spectroscopy
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Applied optics
دوره 45 17 شماره
صفحات -
تاریخ انتشار 2006