Despite the economic woes of the communications sector, some technologies can still stir great interest on Wall Street, as well as in the laboratory. Among the more exciting is the tunable laser. Aimed at wavelength-division multiplexing, tunable lasers can save money while making networks more flexible. Tunable lasers also make it easy to add or delete bandwidth by remote control-with no need to dispatch a service technician-thereby opening the door to a variety of new on-demand services.