Electro-Absorption Modulator Integrated Lasers With Enhanced Signal Injection Efficiency

Abstract

By incorporating a lumped-element impedancematching network on the laser diode carrier/submount, the signal injection efficiency of electro-absorption modulator integrated lasers is significantly improved through the reduction of input return loss. Over a frequency range spanning from 5.8 to 10 GHz, an improvement of approximately 12% to 37% in signal injection efficiency is observed. To avoid increasing the component-count, a unique implementation of the lumped element impedance matching network is proposed.

A 40 Gbps electro-absorption modulator integrated laser modeling method for optical transmitter in ultra-wide band radio-over-fiber systems

“…EAMs are getting more and more attractive for use in both analog and digital high-speed optical communication systems [10] because of their low chirp, low driving voltage, low power consumption, compactness, and strong potential for monolithic integration [2, 11, 13]. An EAM is generally integrated with a DFB laser to form an electro-absorption modulated laser (EML).…”

“…External modulators present various advantages for a photonic link such as a high bandwidth and a lower nonlinear distortion due to the optical frequency chirping commonly impacting a direct modulation of laser diodes. Since the introduction of the relatively cheaper EAM [11], there has been considerable interest in the use of EAMs as transmitters in fiber-optical systems [1, 10, 12]. These devices have replaced the MZM for transmitting optical wireless signal over fiber links because they have the advantages of both a lower cost and a lower biased voltage than MZM [13].…”

Development of a novel broadband impedance matching network for 40 Gb/s electro‐absorption modulators

“…Under reverse bias, the EAMs exhibit a high impedance operation. Because of degraded signal injection efficiency and strong reflection, the high impedance characteristic of the EAMs can limit the high‐speed performance of the device [6, 7].…”

“…Besides, with a “+” shaped microstrip line, the RF return loss of an EAM integrated lasers (EML) is improved for 2.5 Gbps application [7]. Using a “L” type microstrip line, the impedance matching of an EML is realized for frequencies above 10 GHz [6].…”