Thermooptical properties of transversely pumped composite YAG rods with a Nd-doped core

In this paper, we report on analytical, numerical, and experimental studies of the thermally induced optical distortions in transversally diode-pumped Nd:YAG composite laser rods, The calculated distributions of temperature, optical path difference, and stress are compared for two different laser ro ds, a homogeneously doped rod and a composite rod with a hexagonal Nd:YAG c ore in an undoped YAG rod. Our theoretical investigations of the optical pa th difference are experimentally confirmed by using a Mach-Zehnder interfer ometer, It is found that the optical path difference profile of the composi te rod has stronger gradients than those of the homogeneously doped rod, In conjunction with experimental evidence, this paper illustrates that, for p ump powers below 200 W, the amount of birefringence is comparable for both laser rods.