Characterization of an electroabsorption modulator design with high-dynamic range for broadband analog applications

Abstract

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. SPONSOR/MONITOR'S ACRONYM(S) SPONSORING/MONITORING AGENCY REPORT NUMBER AFRL-RY-RS-TP-2008-8 DISTRIBUTION AVAILABILITY STATEMENTApproved for public release; distribution unlimited. PA# AFRL WS 07-0387 SUPPLEMENTARY NOTESPaper published in Proc. of SPIE Vol 6975, 69750N. This material is declared a work of the U. S. Government and is not subject to copyright protection in the United States. ABSTRACTAn electro-absorption modulator (EAM) is designed to optimize dynamic range performance over 20 GHz bandwidth. The single stripe waveguide enables an extremely compact and integrated package to be fabricated with single mode fiber pigtails. The transfer function's shape permits suppression of higher order intermodulation products, yielding a spur-free dynamic range exceeding that of Mach-Zehnder designs. A dilute optical core diverts energy flow from absorbing layers into a low loss waveguide; the 20 dBm optical power tolerance is significantly higher than that o commercially available electro-absorption devices. The tunable performance over 20GHz is characterized and applications are discussed. New approaches to the broadband impedance matching requirements are calculated and the impact on system performance is assessed. SUBJECT TERMS

New prospects for high-power, high-efficiency analog electroabsorption modulators

“…The module was built to handle an optical power of 100mW (+20dBm) over a bandwidth (BW) of 20GHz, with a performance optimized 1 for applications such as radar. 3 Initial bench testing of the DCW EAM chip showed promise, but it needed packaging for performance characterization in non-laboratory conditions. In the new configuration, the RF-modulation layer and optical waveguide are decoupled, posing new challenges to the package-assembly process.…”