Calibration of optical modulators by optical down-conversion

A new method for the calibration of intensity modulators and modulated laser diodes at millimeter-wave frequencies is presented. The method uses an integrated-optic modulator as both a mixer and a frequency doubler. To demonstrate the measurement technique an intensity modulator is calibrated over the band 26.5-40 GHz. The measurement system employs no components exceeding 20 GHz (excluding the RF generator), and with relatively minor modifications measurements in excess of 60 GHz are feasible.<
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