  External-cavity diode lasers are ubiquitous in atomic physics and a wide
variety of other scientific disciplines, due to their excellent affordability,
coherence length and versatility. However, for higher power applications, the
combination of seed lasers, injection-locking and amplifiers can rapidly become
expensive and complex. Here we present a useful, high-power, single-diode laser
design with specifications: $>210\,$mW, $100\,$ms-linewidth ($427 \pm 7$) kHz,
$>99\%$ mode purity, $10\,$GHz mode-hop-free tuning range and $12\,$nm coarse
tuning. Simple methods are outlined to determine the spectral purity and
linewidth with minimal additional infrastructure. The laser has sufficient
power to collect $10^{10}$ $^{87}$Rb atoms in a single-chamber vapour-loaded
magneto-optical trap. With appropriate diodes and feedback, the system could be
easily adapted to other atomic species and laser formats.
