Computational Study of Amplitude-to-Phase Conversion in a Modified Unitraveling Carrier Photodetector

IEEE Photonics Journal

Yue Hu¹  Keith J. Williams²  Meredith N. Hutchinson²  Vincent J. Urick²  Curtis R. Menyuk³  Xiaojun Xie⁴  Joe C. Campbell⁴ 

[1] Department of Computer Science and Electrical Engineering, University of Maryland Baltimore County, Baltimore, MD, USA;Naval Research Laboratory, Washington, DC, USA;University of Maryland Baltimore County, Baltimore, MD, USA;University of Virginia, Charlottesville, VA, USA;

关键词: Photodetector;    amplitude-to-phase (AM-to-PM);    microwave generation.;   

DOI  :  10.1109/JPHOT.2017.2682251

来源: DOAJ

【 摘 要 】

We calculate the amplitude-to-phase (AM-to-PM) noise conversion in a modified unitraveling carrier photodetector. We obtained two nulls as measured in the experiments, and we explain their origin. The nulls appear due to the transit time variation when the average photocurrent varies, and the transit time variation is due to the change of electron velocity when the average photocurrent varies. We also show that the AM-to-PM conversion coefficient depends only on the pulse energy and is independent of the pulse duration when the duration is less than 500 fs. When the pulse duration is larger than 500 fs, the nulls of the AM-to-PM conversion coefficient shift to larger average photocurrents. This shift occurs because the increase in that pulse duration leads to a decrease in the peak photocurrent. The AM-to-PM noise conversion coefficient changes as the repetition rate varies. However, the repetition rate does not change the AM-to-PM conversion coefficient as a function of input optical pulse energy. The repetition rate changes the average photocurrent. We propose a design that would in theory improve the performance of the device.

【 授权许可】

Unknown