Amplified spontaneous emission-application to Nd:YAG lasers

TLDR: In this article, a closed-form model was developed to characterize the spectral and spatial portions of amplified spontaneous emission in a flashlamp-pumped Nd:YAG laser with a threshold of 12 J and a slope efficiency of 0009.

Abstract: Amplified spontaneous emission can seriously degrade the Q-switched performance of a strong four-level transition such as the 1064 /spl mu/m Nd:YAG transition or can even prevent oscillation on a weaker quasi-four-level transition such as the 0946-/spl mu/m Nd:YAG transition To characterize, and thus be able to mitigate, amplified spontaneous emission, a closed-form model is developed By employing a closed-form solution, the differential equations describing both the evolution and decay of the upper laser manifold population density can be solved exactly An advantage of this model is the separation of the spectral and spatial portions of amplified spontaneous emission Gain measurements, as a function of time and pump energy, are compared with the model and good agreement is found With these principles in mind, a flashlamp-pumped Nd:YAG laser was designed to operate at 0936 /spl mu/m At room temperature, a threshold of 12 J and a slope efficiency of 0009 was achieved