Methods of Mode Generation Inside Hollow Core Photonic Crystal Fibers

Microspheres trapped inside Hollow Core Photonic Crystal Fibers (HCPCF) could provide a way to monitor the temperature in hydrogen combustors, thereby helping to provide a warning system for flashback and thermoacoustic oscillations that can lead to expensive combustor damage. The temperature of a particle trapped in a HCPCF may be extracted by the analysis of the particles' motion, which can be in turn controlled by opportune manipulation of the spatial intensity profile of the light in HCPCF. To this aim, an intermodal beating intensity pattern may be created inside the HCPCF using a mixture of LP01 and LP11 modes. In this work, methods of generating the optical modes, which involve the use of spatial light shaping techniques, are presented and analysed. This is an important step to producing a controllable intermodal beating pattern.