Wideband optical waveguide phase modulator is a basic device in high speed or coherent optical fiber communication system. Because of the limit from electrode capacitance, conventional modulators based upon standing wave voltage E / 0 modulation hardly get the bandwidth as wide as several GHz. This paper presents an optical waveguide phase modulator, which takes the advantage of travelling-wave modulator. Its 3dB bandwidth of phase modulation index (5 (peak to peak value) has reached 6 GHz, while the total insertion loss is moderately 5dB in all over the band.
Jihu Peng, Jihu Peng,
"Wideband optical waveguide phase modulation", Proc. SPIE 1230, International Conference on Optoelectronic Science and Engineering '90, 123009 (1 July 1990); doi: 10.1117/12.2294646; https://doi.org/10.1117/12.2294646