ISSN (Print) : 2320 – 3765 ISSN (Online): 2278 – 8875 International Journal of Advanced Research in Electrical, Electronics and Instrumentation Engineering (An ISO 3297: 2007 Certified Organization) Vol. 3, Issue 12, December 2014 10.15662/ijareeie.2014.0312001 Copyright to IJAREEIE www.ijareeie.com 13451 Design of a LW-VCSEL Optical Source Musaddeque Anwar Al-Abedin Syed 1 , Dr. Md. Kamrul Hassan 2 Assistant Professor, Department of Electrical and Electronic Engineering, International Islamic University Chittagong, Dhaka, Bangladesh 1 Assistant Professor, Department of Electrical and Electronic Engineering, American International University- Bangladesh, Dhaka, Bangladesh 2 ABSTRACT: There are a number of reasons why light can be used as an efficient carrier of information. As a result, optical communication has gained much importance over the last few decades. The vertical cavity surface emitting laser (VCSEL) is a low cost light source with attractive performance characteristics such as low power consumption, high speed capabilities at low currents, and a circular output beam. These features have madeVCSEL an established component in digital communication networks as the optical source. In this paper, a 1550nm intra-cavity structure Vertical Cavity Surface Emitting Laser (VCSEL) has been designed using quarter nary compound material of AlGaIn Asin both QW and barrier, but with different compositions, and InP as the substrate. Lattice matching has been obtained in the layers from the substrate upto the top contact layer except the quantum well(QW) layers where small amount of compressive strain of 1.6% has been used. AlGaAsSb/AlAsSb has been used as the DBR material for achieving lattice matching with the substrate, and also for achieving higher refractive index contrast. The active material compositions have been chosen to obtain a peak gain at 1550 nm. The out come of this design is a top emitting VCSEL based on In P substrate using a different structure which is capable of producing 1550 nm light output and which can be constructed easily using widely used epitaxial techniques mixed with the MBE using digital alloy technique for the QW layers. The designed VCSEL is successfully simulated as an optical source, with an error free transmission of 70 km through a single mode optical fiber.The finalstructure of the VCSELis alsosuitablefor useinopticalICs. KEYWORDS: Diode Laser, VCSEL, MQW, DBR, 1550nm, AlGaInAs, Optical Source, Optical Fiber Communication I.INTRODUCTION Light has numerous characteristics for which it can be used as an efficient carrier of information. First, the high carrier frequency (greater than 100 THz in the so-called communication bands) makes it possible to modulate the signal with enormous amounts of information without significantly affecting the properties of the light. Second, the propagation of the light is highly insensitive to electromagnetic interference, andthird, the short wavelength (∼1 μm) makes it possible to propagate the light in optical fibers. With the development of the semiconductor laser [1], the low loss optical fiber [2, 3], and the fiber amplifier [4], fiber-optics have therefore revolutionized the way people communicate. Long wavelength Vertical Cavity Surface Emitting Lasers (LW-VCSEL)have many advantages such aslow loss in optical fibers, low dispersion for 1.5 μm optical fibers, higher eye safe maximum limit power and lower operation voltages [5].Due to all thesewell-known advantages of VCSELs, current trend has been toreplace the edge emitting lasers by VCSELs [6]. Over the years, the common combination of materials for the quantum well (QW) based semiconductoractive layers have beenGaInAsP/InP, for constructing VCSELs for the 1300nm and 1550nm windows, because of the matchedbandgap of the materials. However, GaInAsP QWs, have lower gain and poor temperature performance than GaAs and InGaAs QWs on GaAs [5]. In case of VCSELs emitting in the 1550nm windows,improvements in various characteristics have been obtained by using AlGaInAs active region, such as a larger conduction band offset than theInGaAsP/InP active region [7], andalsoa better temperature performance than GaInAsP QWs [5].According to Yong et. al. [8],InGaAsN and AlGaInAs have good potential as active layer material systems for low-threshold and high speed modulation bandwidth devices, required for next generation low cost communication links. Thereforein this work, AlGaInAs has been chosen as the active material to get better performance. The design of theVCSEL in this work also utilizes thebenefits of intra-