Analysis of optically pumped compact laterally coupled distributed feedback lasers with three symmetric defect regions

Abstract

This article analyzes compact laterally coupled distributed feedback (DFB) lasers with three defect regions. These devices are more flexible and smaller than conventional DFB lasers, having typical lengths between 20 and 50μm and a width less than 1μm (lateral gratings are inserted in a single-mode waveguide). We optimize the defect regions to achieve an improved performance. In other words, an adequate choice of phase shifts may lead to single-mode operation, lower threshold optical power, higher quantum differential efficiency, and more uniform field distribution. This device is designed to operate under optical pumping.

Fractal-Like Square Lattice of Air Holes

“…In order to assess the in-plane transmission properties of the photonic crystal structures, we employ two-dimensional finite-difference timedomain (FDTD) methods. Commercial software (Fullwave from RSOFT company [19]) is employed. Perfect absorbing layers are placed at the borders of the computation area.…”

“…They can sometimes represent natura phenomena better than do conventiona geometric objects [15]. These special geometrical forms have a so been applied to optica devices [16][17][18][19], eading to DFB asers with improved performance [18,19]. Also, fractals have been applied to antennas to produce specially tailored radiation beams [20].…”