Optical Fibre communication less than 20 pages about 2500 words ish 1 Description and Aims of the Project The purpose of this project is to design avalanche photodiodes using III V semiconductors for optical fiber communications Optical fiber communication is a means of transmitting information by converting electrical signals into light via a medium 1 Avalanche photodiodes APDs are the raw materials that can be found in optical detectors which are used in optical fiber communications APD is a reversed biased p n junction that is operated at voltages close to breakdown voltage 2 Breakdown voltage is the voltage reached when an avalanche breakdown has occurred Avalanche breakdown is affected by the ionization of electron hole pairs and occurs under reverse bias in PN diodes it is a continuous process where the electric field across the depletion region increases due to the reverse bias which in turn causes the collision of the charge impurities in the material to increase 2 Avalanche breakdown controls the maximum reverse bias voltage that can be applied to a PN diode 3 Avalanche multiplication and quantum mechanical tunneling of carriers are two mechanisms that can cause safe avalanche breakdown without destroying the diode In this project the avalanche multiplication mechanism will be applied
