A light emitting control apparatus comprises a light emitting element which emits a light when an input electrical signal is converted into a light signal, a monitoring circuit which monitors the output level of the light emitting element, a sample-and-hold circuit which detects a peak value and is put...http://www.google.com/patents/US5978124?utm_source=gb-gplus-sharePatent US5978124 - Light emitting control apparatus and optical transmitter
