Direct Observation of Waveguide Formation in KGd(WO$_4$)$_2$ by Low Dose H$^+$ Ion Implantation


In this letter, a direct measurement of a refractive index change in potassium gadolinium tungstate KGW created by a low-dose ion implantation of 1 MeV hydrogen ions is reported. The characterization was performed using both microreflectivity and Raman spectroscopy measurements. The microreflectivity results show both negative and positive changes in refractive index in the damage region when measuring refractive index along different polarization axes. Micro-Raman spectroscopy analysis shows preservation of the Raman characteristics of KGW in the nondamaged crystal regions. These results show that ion implantation in KGW has a great potential for fabricating waveguide structures in Raman-based photonic devices.

Appl. Phys. Lett. 89, 111116 (2006)