CHARACTERIZATION OF UNI-TRAVELING CARRIER PHOTODIODES FOR HIGH-LINEARITY AND HIGH-SNR APPLICATIONS

A typical uni-traveling carrier photodiode (UTC-PD) and a commercial PIN-PD are compared in the context of the analog performance at 10 GHz in a realistic noise environment. The behavior of the carrier-to-noise ratio (CNR), the linearity, represented by the third-order output intercept point (OIP3). and the spurious free dynamic range are studied as a function of photocurrent. We have found that the increment of the CNR is only minor because of excess noise of the amplifier, as an optical amplifier is used to reach high optical power. However, the OIP3 of the UTC-PD is substantially higher and increases with photocurrent. in contrast to the PIN-PD. Thus, even though the responsivity is lower. it is beneficial to use a UTC-PD to have superior dynamic range. (C) 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 984-987, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25055