A light generating system that comprises a narrow evacuated slot defined
between at least two high index contrast waveguide elements. The
apparatus can be fabricated using a material such as a SOI wafer having
an oxide layer thickness of the order of 1 micron and a top silicon layer
thickness of the order of 100-150 nm. Electrode contacts are provided to
at least two waveguide elements fabricated in the top silicon layer, each
waveguide element having a thickness comparable to the top silicon layer
thickness, a width of some hundreds of nm, and having a slot having
dimensions in the range of 50-200 nm defined therebetween. The length of
the slot is at least as long as the slot width. Charged particles, such
as electrons, that are emitted and accelerated across the slot by an
applied electrical signal provide a source of photons as a consequence of
being accelerated and/or decelerated.