A Multipurpose Flexible Photonic Integrated Micro Device for Space and Earth Applications Based on a Tuneable Resonating Micro Cavity on LiNbO₃

Photonic crystals are attracting great interest because of the possibility to functionalize surfaces and materials and to obtain integrated devices suitable for the implementation of different optical functions. These systems can be used to fulfil a specific function (Filtering, Amplifying, Switching, Shifting, etc.) but can also be integrated in more complex hybrid systems, including optical and electronic signals, suitable for performing more complex functions. The application of such devices can span from Telecommunications, Space Applications to Ambient Safety or Security Monitoring. In this work the design and development of an integrated photonic micro-device, fabricated on single crystal LiNbO₃ substrates, by using non-standard processes such as Deep UV laser lithography and High Energy Ion Implantation techniques, is described. The structure is composed by two linear Bragg Gratings fabricated on a channel or planar optical waveguide. By fixing proper gratings dimensions, it is possible to generate an optical micro-cavity, resonant with specific optical wavelengths. In the case of LiNbO₃ an electric field can be applied along the crystal c-axis, in order to exploit its electro-optical properties and obtain a tuneable effect on both the mirrors and the cavity. In order to generate a multipurpose micro-device, a receptacle of suitable size has been created in between the two mirrors. The receptacle can be filled with different optical items, depending on the function to be accomplished. Design and fabrication details together with preliminary performance tests of the new photonic device will be presented.