Modulation and Switching Architecture Performances for Frequency Up-conversion of Complex-Modulated Data Signals based on a SOA-MZI Photonic Sampling Mixer

TL;DR

This paper presents a comprehensive analysis of a SOA-MZI photonic sampling mixer for frequency up-conversion, demonstrating high conversion gains and evaluating complex modulation formats for high-speed data transmission.

Contribution

It provides both theoretical and experimental insights into the performance of Switching and Modulation architectures in a SOA-MZI mixer, including closed-form gain equations and modulation format evaluations.

Findings

High conversion gains of about 15 dB at 9 GHz achieved.

Conversion to 39 GHz yields lower gains, up to 9 dB.

Maximum bit rates of 1 Gbps (QPSK) and 512 Mbps (16-QAM) meet FEC limits.

Abstract

A theoretical and experimental performance analysis of a Semiconductor Optical Amplifier - Mach-Zehnder Interferometer (SOA-MZI) photonic sampling mixer used as a frequency up-converter is presented employing Switching and Modulation architectures. An active mode-locked laser, generating 2 ps-width pulses at a repetition rate equal to 10 GHz, is used as a sampling source. An optical carrier intensity modulated by a sinusoidal signal at 1 GHz is up-converted to 9 GHz and 39 GHz. High Conversion Gains (CGs) of about 15 dB are demonstrated for the frequency conversion to 9 GHz using both architectures, whereas up to 4 dB and 9 dB for the conversion to 39 GHz employing Switching and Modulation architectures, respectively. Small-signal equations for the up-converted signal in both architectures are formulated and developed, which permit to quantify the CG from closed-form expressions. The numerically calculated CG values are in very good agreement with those obtained experimentally. The validated equations are subsequently employed to explain the performance differences between the two architectures in terms of the CG. Furthermore, signals modulated by QPSK and 16-QAM complex modulation formats at different baud rates are up-converted from 750 MHz to 9.25 GHz and 39.75 GHz and their Error Vector Magnitude is evaluated and compared. The maximum bit rate that meets the Forward Error Correction (FEC) limit is achieved using the Modulation architecture. It is 1 Gbps and 512 Mbps for QPSK and 16-QAM modulations, respectively.