Optical intensity modulators with closely matched frequency responses are required for the realization of an optical adaptive nulling system for microwave/millimeter-wave multi-element antenna systems. Traveling-wave interferometric modulators fabricated in lithium niobate have been demonstrated that track to within 0.03 dB and 0.22 deg in amplitude and phase, respectively, over the 5- to 7-GHz frequency band.
Leonard M. Johnson,
Harold V. Roussell,
Gary E. Betts,
"Interferometric modulators for an adaptive nulling system", Proc. SPIE 1790, Analog Photonics, (26 February 1993); doi: 10.1117/12.141719; https://doi.org/10.1117/12.141719