Can one or more of our more technical savvy folk break down the advantages that POET VCSEL's have over the competitions VCSEL's? Not the typical poet response and advantages but specifically for the VCSEL's. Thanks in advance! Steve
The POET VCSEL is at the heart of the POET platform. The VCSEL itself is part of a structure that incorporates the nFET, the pFET and the thyristor. As such once optimized it can produce very high speed logic at extremely low energy levels.. Right now POET is focused on the most basic aspects of the VCSEL as an optical interface where high speed logic is performed by mature silicon CMOS.
That is it in a nut shell re the POET VCSEL. Also note that POET is now referencing the underlying structure as a DOES. A digital opticalelectonic switch. As such the laser does not function as a typical analog driven VCSEL where the amplitude of the laser output has to be measured to determine a logic signal. This is noted as extinction ratio where much more average energy is required to produce a digital output. Instead POET uses the nFET to produce an electronic signal which produces a digital pulse output (POET makes reference of this capability as achieving infinite extinction ratio…which as I understand it is to pretty much of a holy grail for the VCSEL industry. In addition the geometry of the POET VCSEL is such that single mode operation is achieved. As such the thinnest fiber (single mode) is used which allows the light to be confined within the thin core of the fiber instead of bouncing off the walls of a much wider multimode fiber creating distortion as the light that is bouncing off the walls at steeper angles gets to the detector at the end of the fiber slower than the photons that take a much more direct route in the core of the thin single mode fiber.
In addition the POET VCSEL produces internal gain. No transimpedance amplifier is required and because all of this is achieved within the POET VCSEL structure there are no interconnections required external to the structure for VCSEL operation (no driver circuit). To think of it in the most simplistic of terms you could say that it is self-contained.
