In our most recent paper, my student and I looked at exploiting non-linearity of Graphene in a plasmonic structure for Supercontinuum Generation (SCG).
This work has been exciting to us for many reasons:
- working on 2D materials. Graphene is a quick start and we are exploring other 2D materials and novel materials as well
- exploiting plasmonic effects to go beyond sensing applications
- we found Graphene behaving as a metal without negative permittvity and saw formation of Surface Plasmon Polaritons (SPP) at 300 and 371K. To us this is really exciting and could mean some new Physics lies in wait for exploration.
We generated a multi-octave broadband SC spectrum ranging from 1.5–25 micron at a low input peak power of 1 W.
Typically we expect that at a metal-dielectric interface, SPPs are formed when
k2/k1 = − ε2/ε1 ,
where ε2 and ε1 are the
permittivity of the metal and dielectric respectively. In our case, the permittivity of Graphene is not negative, however we still observe the formation of SPPs. The values we obtained are summarised below:
This performance SC spectrum ranging from 1.5–25 micron was possible due to the high Kerr non-linearity of Graphene and also the tailored waveguide dispersion we obtained.
Look out for more on this…