One-dimensional photonic crystals with mechanical defects fabricated by two-photon polymerization

One-dimensional photonic crystals have been frequently used as optical filters and in sensing technology due to their ability to induce highly reflective photonic bandgaps. Conventionally, at least two materials are required to create the necessary dielectric contrast for photonic bandgaps to form. Recently, one-dimensional photonic crystals fabricated by two-photon polymerization have demonstrated the ability to induce photonic bandgaps with reflectances over 90%. Using this fabrication approach, dielectric contrast is achieved by altering the density of adjacent layers from a single photo-sensitive polymer. The success of this technique has led to the development of design modifications which allow additional spectral control of the photonic bandgap. In this study, we combine these concepts to develop a one-dimensional photonic crystal which includes a mechanical defect for the first time. Mechanical control of this defect allows for the presence of the transmissive defect mode to be actively shifted in and out of the photonic bandgap. The fabrication of this structure as well as its characterization is reported and discussed. The results of this study further support the use of one-dimensional photonic crystals in opto-mechanical applications where switchable narrow transmission bands are desired.