From mabdelg@yahoo.com Fri Nov 15 11:01:45 2002 Return-Path: Received: from web14805.mail.yahoo.com (web14805.mail.yahoo.com [216.136.224.221]) by helios.physics.utoronto.ca (8.9.3/8.9.3) with SMTP id LAA6375093 for ; Fri, 15 Nov 2002 11:01:44 -0500 (EST) Message-ID: <20021115160122.40030.qmail@web14805.mail.yahoo.com> Received: from [64.231.249.36] by web14805.mail.yahoo.com via HTTP; Fri, 15 Nov 2002 08:01:22 PST Date: Fri, 15 Nov 2002 08:01:22 -0800 (PST) From: mohammed abdelg Subject: Presentation: Quantum Cascade Laser To: Aephraim Steinberg In-Reply-To: <200211112112.gABLCNQi010061@courses.ece.toronto.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Status: R Quantum Cascade Laser Abstract Semiconductor lasers are widely used in telecommunication and consumer electronics. In 1994 Capasso's group at Bell Labs pioneered a new type of semiconductor laser known as the quantum cascade laser (QCL). QLC operates with a different lasing process than conventional semiconductor lasers. A conventional semiconductor lasers emits photons as result of recombination between electorns in the condcution band and holes in the valance band. QLC is based on utilization of tunneling process between quantum wells. A quantum well is essentially a semiconductor with relatively low band gap energy sandwiched between semiconductor layers with high band gap energies. Mohamed __________________________________________________ Do you Yahoo!? Yahoo! Web Hosting - Let the expert host your site http://webhosting.yahoo.com