3D printed hollow core terahertz Bragg waveguides with defect layers for surface sensing applications Li, Jingwen ; Nallappan, Kathirvel ; Guerboukha, Hichem ; Skorobogatiy, Maksim Abstract Publication: Optics Express Pub Date: February 2017 DOI: 10.1364/OE.25.004126 Bibcode: 2017OExpr..25.4126L