We realized a multi-duplication of the emission beam generated at the surface by using the excitation of theleaky mode in a TiO2 slanted nanograting layer. In the TiO2 layer, the beam is waveguided along the short-axisdirection of the grating at a specific injection angle Θ. On the surface of the layer, a beam consisting of leakagegenerated during the waveguide is emitted. The emitted beam would have a high optical intensity comparedwith the general emission. Furthermore, it would generate an afterimage for the waveguide direction. In thiswork, we performed angle-resolved measurements to obtain two effects, namely intensity improvement andafterimaging. Subsequently, we identified an appropriate resonance condition for the above leaky radiation onthe 1D waveguide on the surface. Thereby, the resonance peak for the leaky waveguide with ΘFWHM = 8.0–10.0°at Θ = 10° was verified in the measurement. This grating sample is likely to be effective as a novel coupler on abinocular virtual reality (VR) head-mounted display (HMD) based on multiduplication broadband beamemission.