  We report on an interference-filter-stabilized external cavity diode laser
using a gallium-nitride-based violet laser diode. Surface-activated-bonded
glass substrates were employed as cat's eye output couplers in order to
suppress power degradation due to optical damage. From the results of a
long-term frequency-stabilization test, mode-hop-free operation for about one
week was demonstrated. After a continuous operation of about three weeks, the
power degradation was less than 10$\%$. The results show the potential of such
interference-filter-stabilized external cavity diode lasers for practical and
portable quantum technologies such as atomic clocks or atomic interferometers.

Atomic Physics;Optics