Near infrared throughput and stray light measurements of diffraction gratings for ELT-HARMONI - Rodrigues, M; Capone, J; Clarke, F; Earle, A; Foster, T; Lynn, J; Obrien, K; Tecza, M; Thatte, N; Tosh, I; Hidalgo Valadez, A; Lewis, I (Society of Photo-optical Instrumentation Engineers, 2018)