AlInAs/GaInAs SAGM-APD

The fabrication and performance of a graded avalanche photodiode structure with a separate GaInAs photo-absorption layer and AlInAs avalanche region to achieve a pure electron injection are discussed. The quality of AlInAs as the avalanche region has been evaluated by measuring responsivity, response time, and excess noise factor. The 3 dB bandwidth and the excess noise factor correspond to beta / alpha approximately 0.3 in pure AlInAs, decreasing to about 0.1 for an AlInAs/GaInAs MQW structure.<
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