This formula arises from substituting P₁=ER⋅P₀ and solving the system of equations. A few observations: If the extinction ratio is very high (i., ER≫1, then ER−1/ER+1≈1, and OMA≈2Pavg. In practice, the extinction ratio is limited by laser/device physics, so you seldom. Among them, Optical Modulation Amplitude (OMA) is a central figure of merit for digital (on-off) modulation schemes. It indicates the difference between the optical power levels of signal "1" and signal "0" received by an optical module. 23 dB à decrease powers by 2. The Eye mode PAM Outer OMA measurement measures Optical Modulation Amplitude (OMA) with PAM4 (levels 0 and 3), PAM6 (levels 0 and 5), and PAM8 (levels 0 and 7). This measurement can also be made on NRZ waveforms.