A highly scalable approach for producing surface‐enhanced Raman spectroscopy substrates is introduced. The novel method involves assembling individual nanoparticles in pre‐defined templates, one particle per template, forming a high denisity of nanogaps over large areas, while decoupling nanostructure synthesis from placement.

Single-crystal optical waveguides of 4-dimethylamino-N-methyl-4-stilbazolium tosylate (DAST), an organic material with a large electro-optic coefficient, have been obtained. DAST decomposes at its melting temperature, making its growth from the melt difficult. However, graphoepitaxy allows for >1 mm s−1 growth, 1×105 times faster than conventional techniques, and produces crystals of the correct dimensions for optical waveguides, 1–15 μm on a side and 5–10 mm long. The crystals grow with the c-axis normal to the substrate, and with in-plane orientation determined by lithographic patterning. The electro-optic coefficient dn/dE is 600±300 pm V−1 at 1.55 μm wavelength. Optical losses are <10 dB cm−1.

Immersion interference lithography was used to pattern gratings with 22-nm half pitch. This ultrahigh resolution was made possible by using 157-nm light, a sapphire coupling prism with index 2.09, and a 30-nm-thick immersion fluid with index 1.82. The thickness was controlled precisely by spin-casting the fluid rather than through mechanical means. The photoresist was a diluted version of a 193-nm material, which had a 157-nm index of 1.74. An analysis of the trade-off between fluid index, absorption coefficient, gap size and throughput indicated that, among the currently available materials, employing a high-index but absorbing fluid is preferable to using a highly transparent but low-index immersion media.

Surface emission cathodes reported here consist of two electrodes separated by ∼10μm on a negative-electron-affinity glass, Cs2Si4O9. The electrodes consist of a W film suspended over the insulator by a gap of 0–70 nm. When electron emission is initiated with a bias of 0–300 V, between the electrodes, the cathodes continue to emit after the bias is removed and for anode voltages as low as 20 V, electric fields <10Vcm−1. The emission is modeled by the electrons tunneling from the electrode onto the glass surface and from there they are emitted into vacuum. Emission without bias is the result of positive charge in the insulator, which replaces the need for a bias voltage.