Comparison of photodiode nonlinearity measurement systems.

Photodiode nonlinearity measurements using one-, two- and three-tone measurement systems are compared with each other, to investigate the comparison accuracy between setups. The mathematical relationship between each setup is analyzed, and data on multiple devices are compared to find under which conditions the measurements are comparable. It is shown that the three measurement systems can be used interchangeably only when the distortion adheres to the expected mathematical slopes.

Novel directional coupled waveguide photodiode-concept and preliminary results.

A novel photodiode is presented using a directional coupler incorporated with a UTC style photodiode with 0.88 A/W responsivity and 35 dBm OIP3 at 25 mA. The device responsivity is characterized at various photocurrents up to 10 mA and the OIP3 is measured up to 25 mA and 10 GHz.

Behaviors of the third order intercept point for p-i-n waveguide photodiodes.

Waveguide PIN photodiodes with different absorber thicknesses and lengths were fabricated and characterized for linearity. Device A has a thicker absorber and shorter length, resulting in a bandwidth of 20 GHz while device B reduces the absorber by half while maintaining the intrinsic layer thickness and almost doubles the length, resulting in a smaller optical overlap factor and a bandwidth of 10 GHz. Device B shows a significant enhancement in OIP3 with a record high maximum value for a PIN waveguide photodiode of 42.

Three laser two-tone setup for measurement of photodiode intercept points.

The third-order intermodulation product intercept (IP3) has become an important figure of interest for photodiodes in high-performance, externally modulated, analog links. With the desire for highly linear photodiodes comes the need to be able to accurately measure the device without additional variables. The purpose of this work is to redesign the current IP3 setup to accurately measure the third order intermodulation distortions of the photodiode and to also be able to measure the second order intercept point (IP2) using the same setup.