Related Experiment Videos
Frequency-locked, injection-seeded, pulsed narrowband optical parametric generator
Thomas A Reichardt1, Ray P Bambha, Thomas J Kulp
1Sandia National Laboratories, P.O. Box 969, Mail Stop 9056, Livermore, California 94551, USA. tareich@sandia.gov
Applied Optics
|July 2, 2003
Summary
A new infrared laser system was developed for detecting methane gas using differential absorption lidar (DIAL). This frequency-locked optical parametric generator (OPG) precisely targets methane absorption lines for accurate measurements.
Area of Science:
- Infrared Spectroscopy
- Laser Technology
- Environmental Monitoring
Background:
- Differential absorption lidar (DIAL) requires precise wavelength control for accurate gas detection.
- Pulsed optical parametric generators (OPGs) offer tunable infrared output crucial for DIAL applications.
- Methane detection is vital for environmental and safety monitoring.
Purpose of the Study:
- To develop a frequency-locked, injection-seeded, pulsed OPG for short-range infrared DIAL.
- To enable precise measurement of a specific methane absorption transition at 3.2704 microm.
- To create a dual-pulse output for differential absorption measurements.
Main Methods:
- Utilized a periodically poled lithium niobate OPG pumped by a Nd:YAG microlaser.
- Employed a distributed feedback (DFB) diode laser for injection seeding.
- Implemented active frequency locking to a methane absorption feature using derivative spectroscopy.
- Generated a two-pulse sequence with a 100-micros temporal separation.
Main Results:
- Achieved a frequency-locked OPG operating at 3.27 microm, targeting methane.
- Produced a two-pulse output with energies of 5.5 microJ and 5.9 microJ.
- Demonstrated 21 mW average power at an 1818 Hz repetition rate.
- Successfully locked the OPG output to the methane R-branch transition.
Conclusions:
- Developed a viable frequency-locked OPG system for methane DIAL applications.
- The system provides precise wavelength control for targeted gas detection.
- The dual-pulse output facilitates differential absorption measurements, crucial for lidar.