An investigation has been made of improving beam quality of a high power diode pumped solid state rod laser. It was determined that the beam quality is limited by aberrations present in the medium, which may be due to mode-medium effects in the Yb:YAG laser. A diffractive optics propagation model was developed to predict the phase distortions present on the laser wavefront at the resonator mirror. Resonator mirrors were then fabricated with the proper correction applied to correct the distorted wavefront. The beam quality improved from M2 = 2.0 to M2 =1.4.
A power scaling investigation of a Yb:YAG rod laser configured with a stable resonator is described. A dual laser rod architecture was chosen to minimize thermal birefringence. An investigation of the medium was carried out by measuring the aberrations during lasing conditions. The limitation of beam quality seems to be due to aberrations related to the mode-medium interaction. The experiments measured the severity of the aberrations and the Zernike coefficients were determined. A simple model provided some insight into the operation of the laser. It has been noted that under certain conditions, spherical aberration can improve beam quality.
We describe the development of an IR source capable of generating light simultaneously in the 3-4 micrometers and 8-13 micrometers bands. Using a tandem optical parametric oscillator architecture, the output wavelengths arise as the signal and idler, respectively, of an AgGaSe2 based OPO. Both efficiency and tuning of this OPO system are discussed and, in particular, a rapid electrooptic method of tuning both mid-wave and long wave IR bands is described.
A physical model of time, temperature, composition, and wavelength-dependent optical absorption behavior of e-beam pumped Ne/Xe/NF3(F2) plasmas is developed and discussed. A data correlation based on the progressive analysis of results pertaining to increasingly complex mixtures is developed. Comparisons of the derived model with medium absorption data are presented and discussed. Where useful, data relating to fluorescence efficiency and medium gain are used to further develop aspects of the model left obscure by the available data relating to medium absorption.