Spur-free dynamic range measurements of a fiber optic link with traveling wave linearized directional coupler modulators

Two-tone testing was performed on a laboratory fiber optic link with LiNbO/sub 3/ traveling wave linearized directional coupler modulators. The third-order distortion was measured at 500 MHz and 1000 MHz, and the spur-free dynamic range was determined. Two modulator configurations, with either one or two passive bias sections, were tested and the results were compared with measurements of simple directional coupler modulators. A 9.5-11 dB improvement in the dynamic range was found in the links employing the linearized modulators. >