Heterogeneously integrated Vernier laser with 10-nm BCB bonding and their thermal analysis
Optics Express
|February 18, 2026
Summary
Heterogeneously integrated silicon/III-V Vernier lasers use a novel 10-nm divinylsiloxane-bis-benzocyclobutene (BCB) bonding layer. This thin BCB layer enables high-performance lasers comparable to direct bonding, suitable for LiDAR applications.
Area of Science:
- Photonics and optoelectronics
- Materials science
- Semiconductor device physics
Background:
- Heterogeneous integration of dissimilar materials like silicon (Si) and III-V semiconductors is crucial for advanced photonic devices.
- Vernier lasers offer specific advantages in wavelength selectivity and tunability.
- Achieving high performance with thin bonding layers presents significant thermal management challenges.
Purpose of the Study:
- To report the development and characterization of Si/III-V two-ring Vernier lasers utilizing an ultra-thin 10-nm divinylsiloxane-bis-benzocyclobutene (BCB) bonding layer.
- To investigate the thermal performance and output characteristics of these heterogeneously integrated lasers.
- To assess the viability of the 10-nm BCB bonding approach for high-temperature laser applications, such as LiDAR.
Main Methods:
- Fabrication of Si/III-V two-ring Vernier lasers with a 10-nm BCB bonding layer.
- Experimental measurement of laser performance metrics including output power, linewidth, free spectral range (FSR), and side mode suppression ratio (SMSR).
- Measurement of thermal impedance using a novel method for lasers with extensive passive sections.
Main Results:
- The fabricated lasers achieved a double-facet output power of 13.6 mW, a linewidth of 2.6 kHz, an FSR of 40 nm, and an SMSR of 46 dB.
- The thermal impedance was measured to be 45.1 K/W, indicating efficient heat dissipation despite the thin bonding layer.
- Laser modeling predicted performance comparable to directly bonded lasers, with less than 10% power difference beyond thermal rollover.
- Anticipated operation at temperatures up to 120°C with a few mW output power.
Conclusions:
- The 10-nm BCB bonding approach enables high-performance heterogeneous integration of Si/III-V Vernier lasers, comparable to direct bonding.
- The demonstrated low thermal impedance suggests the BCB layer is thermally efficient, enabling robust device operation.
- The potential for high-temperature operation makes this bonding method attractive for demanding applications like LiDAR chipsets.
