Over-67-GHz-Bandwidth Membrane InGaAlAs Electro-Absorption Modulator Integrated With DFB Laser on Si Platform

Abstract

We fabricate a membrane InGaAlAs electroabsorption modulator (EAM) integrated with a distributed feedback (DFB) laser combining direct wafer bonding and epitaxial regrowth of InP-based layers on a silicon-on-insulator wafer. Heterogeneous integration of an InP-based multiple-quantum-well (MQW) layer into the Si photonics simplifies the integration of the O-band EAMs and laser diodes (LDs). EAMs and LDs can be fabricated using the same MQW layer because of the wide operating range and the direct bandgap of the MQWs. A compact and high-speed lumped-electrode EAM can be made because the membrane lateral p-i-n diode structure has low capacitance and a large optical confinement factor. The effective-refractive-index matching between the membrane InP and Si layers enables the DFB laser to be fabricated with a low-loss supermode waveguide whose MQW core was optically coupled to the Si core. The fabricated 100-µm-long membrane EAM has a high modulation efficiency of about 3 dB/V at 1260 nm and E-O bandwidth of over 67 GHz even without a 50-ohm termination. The EAM-integrated DFB laser has a fiber coupled output power of about −2 dBm and clear eye openings with an extinction ratio of 3.8 and 3.2 dB for 100-and 112-Gbit/s non-return-to-zero signals, respectively.

Advancing Photonic Communications: High-Density Integration of a 100 Gb/s O-Band QCSE Modulator on Silicon Substrates

“…Material strain-engineering in stratified media of quantum well and barrier layers, based on semiconductor alloys on silicon (Si) substrates, can enable the O-band modulation by exploiting the QCSE. QCSE modulators have been studied in p-i-n diode forms structured by III/V [14][15][16][17] and Si-Ge [18][19][20][21] stacks, with robust epitaxial growth techniques for the latter due to its inherent similarities with Si. However, even for the more mature Si-Ge stack a butt-coupling waveguide integration is challenging, mainly because of the difference in the core thickness of the passive and the active parts (220 nm in standard silicon-on-insulator (SOI) 5 , ∼ 400 nm-1000 nm in Si-Ge 22 ), while an evanescent coupling format with a Si-Ge taper is not easily controlled in terms of fabrication 18 .…”

Design of high power evanescent quantum dot distributed feedback lasers on Si

“…At the same time, III-V taper significantly increases the complexity of the fabrication process, thus reducing the device yield. Secondly, the both sides of the conventional evanescent QD DFB lasers have the same optical output power, so only about 50% of the output power is effectively utilized [39]. Thirdly, there is little detailed information on the design and fabrication of this platform, which is very different compared to the integration platform of evanescent coupled QW lasers.…”

200 Gb/s Optical-Amplifier-Free IM/DD Transmissions Using a Directly Modulated O-Band DFB+R Laser Targeting LR Applications

“…On the one hand, external modulator-based transmitters such as silicon-photonic [5,6], plasmonic [7][8][9], and thin-film Lithium Niobate-(TFLN) [10][11][12][13] Mach-Zehnder modulators (MZM) or micro-ring modulators (MRM) [14][15][16] have shown excellent performance in terms of bandwidth and modulation linearity for high baud rate operation, however, requiring high-power external light sources to operate. On the other hand, monolithically integrated transmitters such as electro-absorption modulated lasers (EML) [17][18][19][20][21][22][23][24][25] and directly modulated lasers (DML) [26][27][28][29][30][31] with a potentially smaller footprint and lower power consumption, also show promising characteristics in supporting over 200 Gb/s/lane transmissions. Moreover, recent efforts in monolithically integrating laser sources with TFLN modulators have been reported [32].…”