Popis: |
Nonlinear optical techniques for combustion diagnostics place stringent demands on the lasers employed. High resolution techniques require narrow bandwidth, preferably single longitudinal mode (SLM), combined with wide tunability and high power. A particular aim of our work is to provide a suitable device for nonlinear optical spectroscopy in the mid-infra-red for diagnostics of hydrocarbon radicals. We report the development of a laser device with the desired properties and its application to high resolution spectroscopy of combustion species. The system is based on a modeless laser used as a narrow bandwidth amplifier (NBA) of radiation from a widely tunable, SLM, diode laser. When pumped by 200 mJ of energy from a frequency doubled, SLM, Nd:Yag laser the system provides output pulses of up to 30 mJ energy in a transform limited bandwidth of |