Extinction ratio references the difference between the energy of the positive level (transmitted 1) and the negative level (transmitted 0). The greater the ratio is, the wider the separation. The purpose of this application note is to show how the optical extinction ratio is defined and to demonstrate how variations in extinction ratio affect the performance of digital optical. One important parameter that is typically measured with an oscilloscope is extinction ratio (ER), which describes how efficiently laser transmitter power is converted to modulation power. ER is defined as the ratio of the average power used to transmit a logic level “1” to the average power used to. The Extinction Ratio defines how distinct the “on” (logic 1) and “off” (logic 0) states of an optical transmitter are, making it a direct indicator of signal quality in optical transceivers.
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