Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Optimizing linearity in high-speed photodiodes

Published

Author(s)

Josue Davila-Rodriguez, X. Xie, J. Zang, Christian J. Long, Tara M. Fortier, Holly F. Leopardi, Takuma Nakamura, J. C. Campbell, Scott A. Diddams, Franklyn J. Quinlan

Abstract

Analog photonic links require high fidelity, high speed optical-to-electrical conversion for applications such as radio-over-fiber, synchronization at kilometer-scale facilities, and low- noise electronic signal generation. Nonlinearity is a particularly vexing problem, causing signal distortion and excess noise, especially in systems utilizing ultrashort optical pulses. Here we show that photodetectors designed for high power handling and high linearity can perform optical-to-electrical conversion of ultrashort optical pulses with unprecedented linearity over a large photocurrent range. We also show that the broadband, complex impedance of the circuit following the photodiode modifies the linearity significantly. By externally manipulating the circuit impedance, we extend the detector's linear range to higher photocurrents, with over 50 dB rejection of amplitude-to-phase conversion for photocurrents up to 40 mA - more than 1000-fold improvement at the peak of the nonlinear response over other state-of-the-art photodiodes and a significant extension of the attainable microwave power with high linearity by a factor of 4. These results indicate the elimination of the long-standing requirement of precise tuning of the average photocurrent to coincide with a nonlinearity minimum, impacting many microwave photonics applications. Using our technique optical-to- electrical conversion can be performed free of excess phase noise from amplitude-to-phase conversion, opening the door to further understanding of the fundamental limitations to photodetection of optical signals.
Citation
Optica

Keywords

Low noise microwaves, Photodiodes

Citation

Davila-Rodriguez, J. , Xie, X. , Zang, J. , Long, C. , Fortier, T. , Leopardi, H. , Nakamura, T. , Campbell, J. , Diddams, S. and Quinlan, F. (2018), Optimizing linearity in high-speed photodiodes, Optica, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=926418 (Accessed July 13, 2024)

Issues

If you have any questions about this publication or are having problems accessing it, please contact reflib@nist.gov.

Created November 7, 2018, Updated February 22, 2019