Please cite this article in press as: T.P. Negara, et al., Transmission characteristics of a microscale dielectric slab waveguide device with a deep groove and an embedded metallodielectric grating at low terahertz frequency, Optik - Int. J. Light Electron Opt. (2014), http://dx.doi.org/10.1016/j.ijleo.2013.12.015 ARTICLE IN PRESS G Model IJLEO-54200; No. of Pages 4 Optik xxx (2014) xxx–xxx Contents lists available at ScienceDirect Optik jo ur nal homepage: www.elsevier.de/ijleo Transmission characteristics of a microscale dielectric slab waveguide device with a deep groove and an embedded metallodielectric grating at low terahertz frequency Teguh P. Negara a,b , Husin Alatas a,c,∗ , Agah D. Garnadi a,d , Sri Nurdiati d a Research Cluster for Dynamics and Modeling of Complex Systems, Faculty of Mathematics and Natural Sciences, Bogor Agricultural University, Jl. Meranti, Kampus IPB Darmaga, Bogor 16680, Indonesia b Department of Computer Science, Pakuan University, Bogor, Indonesia c Theoretical Physics Division, Department of Physics, Bogor Agricultural University, Jl. Meranti, Kampus IPB Darmaga, Bogor 16680, Indonesia d Computational Mathematics Division, Department of Mathematics, Bogor Agricultural University, Jl. Meranti, Kampus IPB Darmaga, Bogor 16680, Indonesia a r t i c l e i n f o Article history: Received 19 June 2013 Accepted 15 December 2013 Available online xxx Keywords: Slab waveguide Metallodielectric grating FDTD method UPML boundary condition a b s t r a c t We discuss the transmission characteristics of a microscale dielectric waveguide device with a deep groove and an embedded metallodielectric grating illuminated by a continuous wave of TM and TE modes at low terahertz frequency. To study its performance we solve numerically the corresponding Maxwell equations by means of finite difference time domain method with uniaxial perfectly match layer as its boundary condition. By varying the angle of incident, grating filling factor and refractive index of analyte in the deep groove, it is found that the device exhibits a significant transmission enhancement for the TM mode due to the existence of surface plasmon interaction. We also demonstrate its potential application as a biosensor device. © 2014 Published by Elsevier GmbH. 1. Introduction Photonics structure with embedded metallic materials has been widely used in integrated optical devices due to the existence of propagating surface plasmon (SP) at the interface between metal and dielectric materials [1]. Its presence is highly sensitive with respect to the environment changes. Physically, the existence of this phenomenon can be explained as a consequence of a collec- tive oscillation of electrons at the metal-dielectric interface due to transverse magnetic (TM) electromagnetic mode which leads to a large enhancement of electric field around the correspond- ing interface [1,2]. This enhancement is strongly depends on the surrounding of the related metallic structure. Obviously, this phe- nomenon can be applied as a sensing platform [3]. In general, the application of SP is widely considered in biosensing devices such as for cell, protein and bacterial detection such as based on long-range surface plasmon waveguide [4,5] and metallic grating [6]. Indeed, beside its use for biosensing platform, this phenomenon can also be applied for other puposes. It was recently reported in ∗ Corresponding author at: Research Cluster for Dynamics and Modeling of Com- plex Systems, Faculty of Mathematics and Natural Sciences, Bogor Agricultural University Jl. Meranti, Kampus IPB Darmaga, Bogor 16680, Indonesia. E-mail address: alatas@ipb.ac.id (H. Alatas). Ref. [7] that SP has been used to assist a Cu x O photocatalyst to split pure water for H 2 gas production more rapidly. In the meantime, it has also been used to detect the presence of H 2 itself by replacing a cladding segment of an optical fiber with metallic layer as reported in Ref. [8] or using photonic crystal fiber [9]. A photonic structure, namely, a dielectric slab waveguide struc- ture with embedded metallic grating has also been considered to be used for such purposes [10–13]. This structure was shown to have specific performance due to the combination effect of grat- ing and SP properties that could lead to enhanced transmission characteristics [13]. Based on the abovementioned facts, in this paper we discuss the results of our systematic numerical investigation on the performance of a specific microscale photonic structure in the form of a dielectric slab waveguide device with metallodielectric grating embedded on its top, and a deep groove which is assumed to be filled by an analyte. We illuminate the system by continuous electromagnetic waves of TM and TE modes and choose their operational frequency in low terahertz order which is related to the resonance of the most protein vibrational frequencies [14]. Solving the associated Maxwell equations by means of standard finite difference time domain (FDTD) method incorporated with uniaxial perfectly matched layer (UPML) [15] as the corresponding boundary condition, we investigate numerically the transmission characteristics of the corresponding modes with respect to the 0030-4026/$ – see front matter © 2014 Published by Elsevier GmbH. http://dx.doi.org/10.1016/j.ijleo.2013.12.015