Characterization of High-Linearity Modified Uni-Traveling Carrier Photodiodes Using Three-Tone and Bias Modulation Techniques

The linearity performance of a back-illuminated InGaAs/InP modified uni-traveling carrier photodiode with a highly doped p-type absorber is characterized using three-tone and bias modulation measurement techniques. The bias modulation measurement is used to determine the voltage-dependent relative responsivity, R(V), for a range of photocurrent levels. The results confirm that the photocurrent dependence of the third-order output intercept point (OIP3) as determined by the three-tone method is directly related to the dependence of R(V) on photocurrent. The measured OIP3 show a weak dependence on frequency and a high value of 47.5 dBm at 20 GHz is achieved.