Excimer lasers are recognized for their efficiency in the ultraviolet. Fully utilizing the capabilities of the excimer medium, however, has always been a challenging engineering problem. Ultraviolet waveguide lasers combine optical waveguiding concepts, microwave discharge excitation, and excimer laser technology to produce a family of compact lasers with novel operating parameters. These new uv sources find a wide variety of applications in direct-write photoablation, microsurgery, and fluorescence instrumentation. They also can serve as master oscillators in larger excimer systems.