100-Gb/s/λ PAM-4 EAM-Integrated DBR-LD Supporting Multiple Sub-Channels Within 1.29 μm Window

Abstract

We present a distributed Bragg reflector-laser diode (DBR-LD) monolithically integrated with an electroabsorption modulator (EAM) offering a 100-Gb/s pulse amplitude modulation 4-level (PAM-4) signal per sub-channel under a CWDM window of 1.29 µm. For the integrated structure, the DBR-LD and EAM were implemented using a trenched waveguide in the tuning sections for achieving energy-efficient wavelength-tuning and a deep ridge waveguide with an optimized structure for a 100-Gb/s PAM-4 operation, respectively. The fabricated chip shows a threshold current of approximately 12 mA and a tuning range of greater than 13 nm, which corresponds to a wavelength band capable of supporting 16 channels with a 150-GHz grid, while maintaining a side mode suppression ratio of greater than 40 dB. In dynamic tests, the results show clear 100-Gb/s PAM-4 eye openings with an outer extinction ratio of more than 4 dB and a transmitter dispersion eye closure quaternary of less than 1.5 dB for all measured channels.

EAM Integrated Widely Tunable DBR Lasers Based on InGaAlAs/InP MQWs

“…Distributed Bragg Reflector (DBR) lasers have been gaining increasing attention due to their simple tuning method and easy fabrication process, as compared to the external cavity lasers [8] and sampled grating DBR lasers [9]. High-speed modulated DBR lasers are promising low cost devices to meet the demands for high capacity WDM optical communication systems [10,11]. Electro-absorption modulated tunable DBR lasers (TEML) have been demonstrated in previous works [11,13,14].…”

“…High-speed modulated DBR lasers are promising low cost devices to meet the demands for high capacity WDM optical communication systems [10,11]. Electro-absorption modulated tunable DBR lasers (TEML) have been demonstrated in previous works [11,13,14]. High speed data can be transmitted for a longer distance by using these externally modulated lasers than using directly modulated DBR lasers [10].…”