Organic μ cavities based on thermally evaporated TeOx-LiF distributed Bragg reflectors

We report on the realization of high-quality organic microcavities consisting of distributed Bragg reflectors based on lithium fluoride (LiF) and tellurium dioxide (TeOx) deposited by thermal evaporation. The materials are transparent in the range of 350 nm-5 mum and have an evaporation temperature of about 1000 K. The large difference in the refractive index (about 0.9 in the visible and near-infrared range) allows one to obtain reflectivity higher than 99% over a spectral region about 200 nm wide with a small number of periods. The mirror deposition technique is suitable for the fabrication of organic quantum microcavities in a single deposition process. Three fully evaporated organic lambda cavities with Phyrrometene 580 as the active material are described. The cavities show a Q value of up to 300, good uniformity, and reproducibility.