1. Institut Teknologi Bandung, Department of Physics, Jl. Ganesa 10, Bandung, Indonesia
2. Institut Teknologi Sumatera, Department of Physics, Jl. Terusan Ryacudu, Lampung Selatan, Indonesia
3. Universitas Negeri Padang, Department of Physics, Jl. Prof. Hamka, Padang, Indonesia