Figure 6
From: Negative-index gratings formed by femtosecond laser overexposure and thermal regeneration

Negative-index FBG during short-term temperature cycling.
Right axis: measured dip wavelength λD. Left axis: transmission loss at λD.
From: Negative-index gratings formed by femtosecond laser overexposure and thermal regeneration
Negative-index FBG during short-term temperature cycling.
Right axis: measured dip wavelength λD. Left axis: transmission loss at λD.