Optik 126 (2015) 3656–3658 Contents lists available at ScienceDirect Optik jo ur nal homepage: www.elsevier.de/ijleo Simulation studies for reflected light of polymer waveguide for realisation of temperature C.S. Mishra, G. Palai ∗ Gandhi Institute for Technological Advancement (GITA), Bhubaneswar, India a r t i c l e i n f o Article history: Received 17 September 2014 Accepted 30 August 2015 Keywords: Polymer waveguide Temperature Reflectance Reflected energy a b s t r a c t The variation of reflected energy with temperature in polymer waveguide on silicon substrate is presented in this paper. To compute reflected energy from polymer waveguide structure, reflectance from such waveguide is simulated using plane wave expansion method. Simulation result revealed that reflectances as well as reflected energies vary linearly with respect to temperature, which leads to an accurate realisation of temperature in the polymer waveguide. © 2015 Elsevier GmbH. All rights reserved. 1. Introduction The burgeon of optical communication and photonic infor- mation revolution are becoming major role in the field optical science and technology. To realise the same communication and information, optical waveguide plays vital role. As far as optical waveguide is concerned, it is made of different materials. Of these, polymer materials exhibit various favourable properties for the sake of waveguide technology [1]. There is a great potential for the use of polymers in terms of optical properties, cost effective and processing feasibility [2]. With regard to fabrication of poly- mer waveguide, various parameters including temperature play an important role for manufacture process [3]. With respect to impor- tance of temperature in polymer wave guide on silicon substrate, this paper realises, the effect of temperature on same waveguide with the help of reflected signal. To realise this, we propose an experimental setup by which one can investigate the temperature in polymer waveguide. The experimental setup is shown in Fig. 1. To make an understand the temperature effect in the polymer waveguide structure, we have chosen three types of commer- cial polymer such as S 1 (polymethylmethacrylate (PMMA)), S 2 (epoxy resin) and S 3 (Polystyrene). Here light source having wave- length 1550 nm is incident on polymer waveguide, which is placed on silicon substrate. Then some amount of light gets reflected from the waveguide structure and it is measured at detector. Here heater is used to apply heat to the polymer waveguide. ∗ Corresponding author. Tel.: +91 9439045946. E-mail addresses: gpalai28@gmail.com, g pallai@yahoo.co.uk (G. Palai). Temperature in the polymer waveguide depends on heat which is a function of reflected energy, so the principle of measure- ment is the variation of reflected energy from such waveguide with respect to temperature. Since heat is being applied to polymer waveguide structure, temperature influences the struc- ture parameters (refractive indices and thickness) to find out reflectance [4,5]. As far as thickness of such waveguide with respect to different temperature is concerned, it is almost con- stant for the same heat, however its refractive indices changes with the change of temperature. Here the thickness of silicon substrate is taken of 2 mm. The variation of refractive indices of different polymer samples with temperature is shown in Table 1 [6]. Table 1, represents the variation of refractive indices of S 1 , S 2 and S 3 with respect to different temperatures, and varies from 30 ◦ C to 80 ◦ C at the wavelength 1550 nm. Here the thickness 6.76 m, 8.13 m and 19.37 m are considered for samples 1, 2 and 3 respec- tively. 2. Simulation and discussion Using data from Table 1 and with the help of plane wave expan- sion method, simulation is made to obtain reflectance of such polymer waveguide with different temperature, which varies from 30 ◦ C to 80 ◦ C [7]. The simulation result for temperature 30 ◦ C of S 1 , S 2 and S 3 is shown in Fig. 2(a)–(c) respectively. Simulation results for other temperatures (35 ◦ C, 40 ◦ C, 45 ◦ C, 50 ◦ C, 55 ◦ C, 60 ◦ C, 65 ◦ C, 70 ◦ C, 75 ◦ C, and 80 ◦ C) are also done but not shown here. Fig. 2(a)–(c) represents the graph between reflectance (Arbi. Unit) along the vertical axis with respect to wavelength http://dx.doi.org/10.1016/j.ijleo.2015.08.256 0030-4026/© 2015 Elsevier GmbH. All rights reserved.