Tuning of an active photonic crystal cavity by an hybrid silica/silicon near-field probe

The influence of a near-field tip on the spectral characteristics of a resonant mode of an active photonic crystal micro-cavity was investigated. The wavelength shift of the mode was theoretically and experimentally demonstrated and evaluated as a function of the nature and the position of the tip above the cavity. Experiment showed that the shift induced is ten times higher with a Si-coated silica probe than with a bare silica tip: a shift until 2 nm was reached with Si-coated tip whereas the shift with bare silica tip is in the range of the tenth of nanometer, for wavelengths around 1,55 microm.