Analysis of incident light scattered by triangle crack on fused silica and Nd-doped phosphate glass surfaces

Finite difference time domain (FDTD) method is used to simulate the incident light scattered by planar cracks with triangular cross-section on fused silica and Nd-doped phosphate glass surfaces. When the incident light is TE mode, the maximum electric field is in the glass. When the incident light is TM mode, the maximum electric field locates inside the crack. The maximum electric field enhancement located at output surface is much higher than that at input surface for both modes. Cracks under TE illumination lead to the maximum electric field when the incident light is totally internally reflected by the crack and by the surface successively. The maximum electric field on rear surface increases with either larger crack width or deeper crack depth.