Technical Note: Extinction Ratio Benchmark Testing for 10 Gbps NRZ Data Modulation
(PDF, 185 KB)

Testing was performed on a dual cascade of Mach Zehnder modulators to assess the effects of instrument limitations on ER measurement. When 2 of the modulators were switched on and off by the digital data, the dB attenuation of the two modulators in cascade doubled from what one modulator provided.

Application Note: Bias Control for External Modulators used in Digital Data Transmission Applications
(PDF, 720 KB)

With the introduction of digital modulators and related applications, active bias control of digital external modulators is essential. This application note describes the JDSU technique for digital bias control.