Fabrication and modification of photonic structures with focused ion beam

Focused ion beam (FIB) is a versatile tool for maskless micro- and nanostructuring [1]. Structures from 10 nm to 100 pm can be fabricated on many different substrates. In this paper we show applications of FIB patterning to photonic elements on Si, InP and optical glass fibers. For each structure, emphasis will be put on the fabrication methods and challenges to optimize the final result. FIB is very well suited for structuring on optical fibers, where other methods would require several processing steps, such as spinning or deposition of photoresist on the facet and lithography. We show that FIB is able to produce smooth curved shapes with good accuracy and reproducibility.