The next 3 decades saw the development of quartz clocks as precision time standards in laboratory settings; the bulky delicate counting electronics, built with vacuum tubes, limited their use elsewhere.
This crystal oscillator creates a signal with very precise frequency, so that quartz clocks are at least an order of magnitude more accurate than mechanical clocks.
This added energy compensates for signal losses and allows surface plasmons to propagate freely along the waveguide, just like the energy supplied by a battery keeps a quartz clock ticking.