Master internship Modelling and characterizing ultrafast tunable filters

Context :
Spectral filtering of optical waves is crucial to many fields, from biomedical imaging to satellite communication. In fluorescence microscopy for instance, precisely designed filters are required to separate the faint fluorescence emission from the strong excitation light. Yet, most filters are created through thin film (metallic or dielectric) deposition and are therefore passive meaning their optical properties are constant in time. Moreover, the spectral transfer function is usually uniform across the entire filter surface. Spatially variable filters can be
manufactured using gradient masks during the deposition process, but more complex shapes remain beyond the reach of current fabrication techniques.

In this project we aim at creating a new generation of filters whose properties can be dynamically controlled in space and time. These new active filters will be based on a FabryPérot cavity coupled to ultrasound transducers. A multi-wave process can indeed tune the local property of the cavity to alter its optical filtering, allowing different wavelengths to go through at different positions on the filter.

MasterCall_Fresnel_dynamicFilter;