  We present the design and performance characterization of an external cavity
diode-laser system optimized for high stability, low passive spectral
linewidth, low cost, and ease of in-house assembly. The main cavity body is
machined from a single aluminum block for robustness to temperature changes and
mechanical vibrations, and features a stiff and light diffraction-grating arm
to suppress low-frequency mechanical resonances. The cavity is vacuum-sealed,
and a custom-molded silicone external housing further isolates the system from
acoustic noise and temperature fluctuations. Beam shaping, optical isolation,
and fiber coupling are integrated, and the design is easily adapted to many
commonly used wavelengths. Resonance data, passive-linewidth data, and passive
stability characterization of the new design demonstrate that its performance
exceeds published specifications for commercial precision diode-laser systems.
The design is fully documented and freely available.
