Near-field coupled butterfly antenna

I build near-field microscopes, and on the vanishingly small chance that you are curious, this is what the business end of one of them looks like. This is an SEM image of a side view of a metal coated optical fiber tip - light is coupled into the other end and travels down a glass fiber which has been coated on the outside with gold. That's the bumpy surface you see.

To make one of these tips, the end of the glass fiber is etched in truly nasty acids (HF) until it forms a pencil tip, and then this is overcoated with 500 nm of gold. The gold is there to confine the light inside the glass taper. The end of this is then sliced off using a focused ion beam milling machine to form a tiny aperture at the end of the tip, which serves as the illumination source in this type of microscope.

To make things even fancier, and for no other reason, I then grew a butterfly antenna on top of this aperture - this is two little tips that you see coming off the front of the tip. They are situated on top of the aperture, and in theory, the light should be greatly concentrated in the space in between the two probes. It didn't work in practice, and I'm not quite sure why, except that 99% of the things I try don't work. So that was two months of work for nothing. See my motto below for a generalization of this principle.