Figure 5
From: Control of the interaction strength of photonic molecules by nanometer precise 3D fabrication
Fabrication and characterization of photonic molecules. (a) Schematics of the photonic stack. The patterns are fabricated in the bottom SiO2 layer before deposition of DBR 1. A dye solution (0.1% Coumarine in toluene) acts as optically active medium. (b) Topography of the t-SPL written pattern consisting of 6 × 6 pairs of 3D Gaussian patterns (c) Close-up of a twin Gaussian structure after t-SPL (top) and after transfer into SiO2 and DBR deposition. (d) Average Cross-sections (symbols) along the first lines of twin Gaussian structures in PPA for Δx = 800, 640, 480, 320, 160, and 0 nm. Lines indicate the target pattern. (e) Fluorescence spectrum (black line) of a photonic molecule for Δx = 480 nm separation of the Gaussians. Colored lines indicate Lorentzian fits. The spectral splitting Δλ is a measure for the coupling strength ΔE of the two microcavities. The peak at 476 nm corresponds to the unstructured part of the sample which acts as a planar Fabry-Perot cavity. (f) ΔE as a function of the distance between the Gaussian centers. The error bars are given by the standard deviation of the measurements of the 6 nominally identical devices. The solid line is a linear fit to the data to guide the eye. The orange symbols are the results from ab-initio numerical simulations.
