12-15 July 2011
Saint George Hotel
Africa/Johannesburg timezone

Demonstration of a wavelength tuneable mid-IR molecular laser

13 Jul 2011, 12:30


Oral Presentation Track C - Lasers, Optics and Spectroscopy LOS


Mr Wayne Koen (CSIR National Laser Centre)


To our knowledge, we have demonstrated the first optically pumped tunable HBr oscillator lasing on both the P- and the R-branches. Through the implementation of an intra-cavity diffractive grating, we could tune the wavelength over a range of 538 nm from 3872 nm to 4410 nm. A single-frequency Ho:YLF ring laser and amplifier system was used as pump source. The oscillator was pumped in a double pass configuration with 50 mJ, 2064 nm pulses at a repetition rate of 50 Hz. The HBr was kept at 52 mBar, 20 degrees Celsius in a 510 mm tube. The resonator cavity consisted of a flat output coupler mirror with a reflectivity of R=80% at 4 μm, and a high-reflective coating at 2 μm. The input coupler mirror had a concave curvature of 5 m and was coated to be highly reflective at 4 μm and highly transmissive at 2 μm to allow pumping of the HBr. The input coupler mirror was slightly tilted to reflect light unto a flat mirror which in turn reflected unto the diffractive grating which was blazed at 5 μm. The diffractive holographic grating therefore acted as the backreflector mirror, and the wavelength could be selected by rotating the grating. Lasing was demonstrated on eight lines of the P-branch with wavelengths ranging from 4102 nm to 4410 nm, and five lines of the R-branch ranging from 3872 nm to 3999 nm. The highest output energy for the given pump power was 1.1 mJ at 4131 nm.

Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)? Yes
Level (Hons, MSc, <br> &nbsp; PhD, other)? MSc
Consider for a student <br> &nbsp; award (Yes / No)? No

Primary author

Mr Wayne Koen (CSIR National Laser Centre)


Mr Cobus Jacobs (CSIR National Laser Centre) Dr Daniel Esser (CSIR National Laser Centre) Dr Hencharl Strauss (CSIR National Laser Centre) Dr Lourens Botha (CSIR National Laser Centre)

Presentation Materials

There are no materials yet.