Impact of length and thickness of active region on radiated output power of InP/InGaAsP laser

A double heterostructure light amplification by stimulated emission of radiation device is designed from two different semiconductor materials. The material used for the active region is InGaAsP and is nearly lattice matched with InP acting as the bulk. We have designed the device in order to observe the impact of length and thickness of active region on radiated output power, photon density and the changes in the radiation pattern of the active region with the variation of length and thickness of the active region. A proper octagonal coherent monochromatic radiation pattern is observed as we reduce the thickness but with the variation of length of the active region, the radiation pattern seems to get disturbed. For the anode voltage of 1.7V, the maximum light intensity achieved from the Fabry-Perot laser is 2.72×108 and is obtained at a wavelength of 1.21µm. In this regard we have studied the variation of reflectivity as function of length of the active region.