Influence of thermal annealing on the properties of proton implanted diamond waveg

Abstract

We have studied guiding performance of 2-MeV proton implanted diamond waveguides as a function of implantation fluence and annealing temperature. Raman spectra show that the change in refractive index (D~n) cannot be ascribed to any single defect. Instead, the normalized intensity of the 1332 cm 1 Raman line (IRaman) has been adopted as a generic parameter to quantify the structural damage caused by implantation. IRaman is experimentally shown to be an indicator of guiding performance. Of all the fabrication conditions, IRaman ¼ 0.27 in the guiding region produces the largest transmission and is achieved by implantation at fluence of 1 1016 cm 2 followed by annealing at 600℃. Experimental observations have been supported by the reconstruction of mode profiles with finite element simulation using IRaman. A single linear relationship of D~n¼ (6.1 þ 8.5i) 10 3 , (1 IRaman) is employed to simulate all of the experimental mode profiles. Our use of proton beam writing and the measured IRaman is a potential technique to design and manufacture light-guiding structures directly in bulk single crystal diamond.