A simple, reliable, linearly polarized laser source with very high beam quality is demonstrated using standard diode-side-pumped Nd:YAG modules. The laser produced 30 W of output power with beam quality factor ????2<1.15 over the entire range of input powers and beam quality of 1.02 at the laser operation point. This is, to our knowledge, the highest beam quality for a dynamically stable high-power laser that uses an optically isotropic crystal. The laser was used as a pump source for an optical parametric oscillator based on a periodically poled lithium niobate, producing wavelength in the 1.5???3.8 ??m range.Funda????o de Amparo ?? Pesquisa do Estado de S??o Paulo (FAPESP)Coordena????o de Aperfei??oamento de Pessoal de N??vel Superior (CAPES)Conselho Nacional de Desenvolvimento Cient??fico e Tecnol??gico (CNPq)FAPESP: 06/53713-0; 12/11437-8CAPES: COFECUB 710_11 081_2013CNPq: 2012_6 402241