Heterogeneously integrated III-V laser on thin SOI with compact optical vertical interconnect access

Area of Science:

• Photonics
• Materials Science
• Electrical Engineering

Background:

• Heterogeneous integration of III-V materials on silicon is crucial for advanced photonic devices.
• Silicon photonics offers miniaturization and integration capabilities.
• Developing efficient and compact laser sources on silicon platforms is a key challenge.

Purpose of the Study:

• To report a new heterogeneously integrated III-V/Si laser structure.
• To demonstrate efficient optical vertical interconnect accesses (VIAs) between III-V and silicon layers.
• To characterize the performance of the fabricated Fabry-Perot (FP) laser.

Main Methods:

• Low-temperature, plasma-assisted direct wafer bonding of III-V semiconductor layers onto a silicon-on-insulator (SOI) wafer.
• Etching to form a III-V ridge waveguide gain section on silicon.
• Tapering of III-V and SOI layers to create optical VIAs for light coupling.
• Fabrication and characterization of the heterogeneous III-V/Si FP laser.

Main Results:

• Continuous-wave lasing achieved at room temperature with a threshold current of 65 mA.
• Slope efficiency from a single facet measured at 144 mW/A.
• Maximal single facet emitting power of approximately 4.5 mW at 100 mA.
• Side-mode suppression ratio (SMSR) of approximately 30 dB.

Conclusions:

• The demonstrated heterogeneously integrated III-V/Si laser structure is viable.
• Efficient light coupling is achieved via optical VIAs.
• This technology enables more complex laser configurations for on-chip subsystems and various applications.