Enhanced Dynamic Range in a Directly Modulated Analog Photonic Link

Abstract

We demonstrate a directly modulated analog photonic link (APL) capable of a high multioctave spurious-free dynamic range (SFDR). The APL consists of a pair of laser diodes, modulated in a push-pull manner, and a balanced photodetector aiming at suppressing the second-order intermodulation distortion (IMD2). In a wide frequency range of 600 MHz (2.60-3.20 GHz), an IMD2 suppression as high as 23 dB and an improvement of 5-18 dB of the second-order SFDR, relative to a conventional single arm photonic link, have been achieved. In this frequency range, the APL SFDR is in excess of 116 dBmiddotHz2/3 .