Abstract

In addition to the growing interest within the semiconductor industry, atomic layer deposition (ALD) has also become an attractive tool to engineer and manipulate with extreme precision the complex dielectric architecture of threedimensional photonic crystals (PCs), such as synthetic opals [1,2]. As a result of the ability to manipulate the dielectric network at the nanoscale, the optical properties of the PC can be adjusted with an unsurpassed degree of flexibility as a means to achieve, for example, large photonic band gaps in the visible or infrared. Very recently, we proposed to apply this technique to 2D PC slab waveguides. Experimental data and 3D-finite-difference time-domain (FDTD) simulations demonstrated that progressive conformal deposition of thin dielectric layers of TiO₂ within the air holes of the patterned structure, as shown in Fig. 1(a), not only allows precise tuning of band frequency, but also dispersion properties. This technique enables the fonnation of multi-layered dielectric PC waveguides, and was found to be an effective pathway to modify the group velocity so as to obtain ultra-slow light or other optical effects, where greatly enhanced light-matter interactions can be exploited [3].

© 2007 IEEE