Numerical analysis of resonant and lasing properties at a defect region within a random structure

We propose a simple structure for manipulating resonant conditions in random structures, in which a defect region where no scatterer is set is deliberately made in the structure. By employing a two-dimensional finite-difference time-domain method including rate equations, we examine the resonant and lasing properties observed at the defect region by changing the filling factor of scatterers. From the numerical results, we confirm that a distinct localized spot at the defect can be realized by determining an optimal filling factor and scatterer size and selecting the appropriate defect size. (C) 2009 Optical Society of America