Second-harmonic generation in He+-implanted gadolinium calcium oxoborate planar waveguides

Area of Science:

• Nonlinear optics
• Materials science
• Waveguide fabrication

Background:

• Ca4GdO(BO3)3 is a promising material for nonlinear optical applications.
• Ion implantation is a technique used to create optical waveguides.
• Understanding the optical properties of ion-implanted materials is crucial for device development.

Purpose of the Study:

• To investigate second-harmonic generation (SHG) in Ca4GdO(BO3)3 waveguides.
• To determine if the nonlinear properties of Ca4GdO(BO3)3 are preserved after helium ion implantation.
• To explore the feasibility of using ion-implanted Ca4GdO(BO3)3 for nonlinear optical devices.

Main Methods:

• Fabrication of a planar waveguide in Ca4GdO(BO3)3 using 2-MeV helium ion implantation.
• Type I noncritical phase matching was achieved for an 823-nm fundamental wave propagating along the y-axis and polarized along the z-axis.
• Second-harmonic generation was measured using a continuous-wave Ti:sapphire laser.

Main Results:

• Successful demonstration of second-harmonic generation in the ion-implanted Ca4GdO(BO3)3 waveguide.
• Effective nonlinear optical activity was observed at relatively low pumping power.
• The results confirm that the material's nonlinearity is maintained within the guiding region post-implantation.

Conclusions:

• Ion-implanted Ca4GdO(BO3)3 waveguides exhibit second-harmonic generation.
• The nonlinear optical properties of Ca4GdO(BO3)3 are robust and remain functional after ion implantation.
• This work paves the way for developing novel nonlinear optical devices based on ion-implanted Ca4GdO(BO3)3.