Abstract
In the last decades great interest has been devoted to photonic crystals aiming at the creation of novel devices which can control light propagation. In the present work, two-dimensional (2D) and three-dimensional (3D) devices based on nanostructured porous silicon have been fabricated. 2D devices consist of a square mesh of 2 μm wide porous silicon veins, leaving5×5 μm square air holes. 3D structures share the same design although multilayer porous silicon veins are used instead, providing an additional degree of modulation. These devices are fabricated from porous silicon single layers (for 2D structures) or multilayers (for 3D structures), opening air holes in them by means of 1 KeV argon ion bombardment through the appropriate copper grids. For 2D structures, a complete photonic band gap for TE polarization is found in the thermal infrared range. For 3D structures, there are no complete band gaps, although several new partial gaps do exist in different high-symmetry directions. The simulation results suggest that these structures are very promising candidates for the development of low-cost photonic devices for their use in the thermal infrared range.
Highlights
The concept of photonic crystal was proposed and discussed theoretically several decades ago [1, 2]
Lightwaves experience periodic perturbations when they propagate through these structures, analogous to electrons in a solid crystal [3,4,5]. This analogy suggests that the dispersion of electromagnetic waves in a photonic crystal can be described in terms of photonic band structures (PBSs)
The 2D periodic dielectric structures that have been fabricated consist of a square mesh of 2 μm wide porous silicon veins, leaving 5 × 5 μm square air holes. 3D structures share the same design multilayer porous silicon veins are used instead, providing an additional degree of modulation
Summary
The concept of photonic crystal was proposed and discussed theoretically several decades ago [1, 2]. Photonic crystals can be described as periodic dielectric structures exhibiting frequency ranges over which electromagnetic waves are not allowed to propagate. The refractive index of PSi can be controlled by changing the porosity of the layers [14] In this regard, there are several models that relate the porosity of a PSi layer and its refractive index, such as the Maxwell-Garnett [15] or the Bruggeman models [16]. There are several models that relate the porosity of a PSi layer and its refractive index, such as the Maxwell-Garnett [15] or the Bruggeman models [16] This last one is used in this work and relates porosity and effective refractive index through the following expression: Cu grid.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
