CCl(2)F(2) optical filter for a TEA CO(2)-laser-pumped NH(3) laser

Area of Science:

• Optics and Photonics
• Laser Physics
• Chemical Physics

Background:

• Ammonia (NH3) lasers are valuable light sources in the mid-infrared region.
• Efficiently filtering pump radiation is crucial for optimizing laser performance and minimizing unwanted energy deposition.

Purpose of the Study:

• To investigate the efficacy of dichlorodifluoromethane (CCl2F2, Freon 12) as an optical filter for a transversely excited atmospheric (TEA) CO2-laser-pumped NH3 laser.
• To assess the impact of CCl2F2 filtration on the NH3 laser's output characteristics and residual pump energy.

Main Methods:

• Utilized a 5-cm-long cell filled with CCl2F2 at 70 Torr as an optical filter.
• Employed a TEA CO2 laser operating on the 9R(30) line to pump the NH3 laser.
• Analyzed the NH3 lasing lines and measured residual pump energy before and after filtration.

Main Results:

• CCl2F2 successfully filtered the optical output of the NH3 laser in the 11.7 to 13 micrometer wavelength range.
• NH3 lasing lines spanned from P(4,K) at 11.7 microm to P(8,K) at 13 microm.
• Residual pump energy was reduced from 1 Joule to a few millijoules without diminishing NH3 laser power.

Conclusions:

• Dichlorodifluoromethane (Freon 12) serves as an effective optical filter for NH3 lasers pumped by TEA CO2 lasers.
• This filtration technique enhances laser efficiency by removing residual pump energy.
• The CCl2F2 filter allows for tunable operation of the NH3 laser across a specific mid-infrared spectral band.