Extinction ratio, when used to describe the performance of an optical transmitter used in digital communications, is simply the ratio of the energy (power) used to transmit a logic level '1', to the energy used to transmit a logic level '0'. The extinction ratio may be expressed as a fraction, in dB, or as a percentage. For a graphical description, the eye-diagram is commonly. Among them, Optical Modulation Amplitude (OMA) is a central figure of merit for digital (on-off) modulation schemes. This article explains OMA from first principles, shows how to compute it, relates it to other metrics like extinction ratio, and discusses its role in real optical transceivers. More importantly, Extinction ratio (ER) is the key parameter to describe the performance of an optical transmitter for the SDI video world. Extinction rat o (ER) indi-cates how well available laser power is converted to modula-tion power the NRZ eye. Laser => Which type should be used? Laser Driver: Photodiode => use of PIN or Avalanche (APD) ? TIA and MA:.
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