Integrated Photonics Platforms
![Fabricated silicon nitride integrated photonics circuits.](/sites/default/files/styles/ifde_wysiwyg_full/public/rdgroup/image/2022-12/Integrated%20Photonics%20colorful%20circuits%20image.jpg?itok=RVl-9u8C)
Lincoln Laboratory has developed world-class photonic integrated circuit platforms and active and passive component libraries. Our main platforms are a silicon nitride and alumina platform covering 370–1100 nm light and a silicon nitride platform aimed at the telecom bands. Both platforms include hybrid integration of active devices. We also have a silicon photonics platform and are developing a midwave infrared photonics platform.
Key features
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Low-loss, flexible material platforms cover a wide wavelength range (near-visible ultraviolet to midwave infrared)
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Hybrid and heterogenous integration allow for a combination of best-in-class devices
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Fabrication using 90-nm CMOS node on 200-mm wafers
Our integrated photonics platforms are fabricated on 200-mm wafers using our 90-nm toolset in our cleanroom that has ISO 9001:2015 Certification. Our electron-beam lithography capabilities enable sub-90-nm features as needed. Extensive compound semiconductor fabrication and packaging facilities allow for the fabrication and integration of III-V and other devices. Flexible combination of fabrication modules is available.
Silicon Nitride and Alumina Visible Light Platform
![Optical microscope image of chip simultaneously illuminated with 7 wavelengths from 405–1092 nm, fabricated using the silicon nitride and alumina visible light platform (370–1100 nm).](/sites/default/files/rdgroup/image/2022-12/SiN%20Al.png)
Our visible light platform is designed to cover optical wavelengths from 370–1092 nm. A mature passive component library provides fundamental devices at > 15 wavelengths throughout this band. Silicon nitride waveguide losses are < 0.3 dB/cm from the yellow to near infrared and < 0.1 dB/cm at 1100 nm. Alumina losses are in the 1–3 dB/cm range for the near-ultraviolet to the green. This platform supports multiple metal layers, including a ground plane under the photonics layers, and can be combined with silicon-based detectors and thermal heaters.
Silicon Nitride RF Photonic Platform
![Optical microscope image of thermally tunable micro-ring resonators for 1550 nm light (waveguide loss ~0.13 dB/cm) fabricated using the silicon nitride platform.](/sites/default/files/rdgroup/image/2022-12/SiN.png)
Our RF photonic platform is aimed at the telecom bands and optimized for RF, lidar, and sensing applications. Waveguide propagation losses are in the 0.1–0.2 dB/cm range, and an extensive component library includes reconfigurable filters, mode-division (de)multiplexers, and splitters among other components. We have demonstrated > 400 mW of optical power handling (measurement limited) and 10 kHz thermal tuning. Flip-chip integrated III-V lasers have shown in-waveguide powers up to 300 mW. Heterogenous integration of lithium niobate and III-V devices is in development.
![Optical microscope image of flip-chip bonded indium phosphide lasers. Hybrid integration includes pick-and-place and thin-film layer transfer.](/sites/default/files/rdgroup/image/2022-12/Flip-chip%20InP.png)
Other Platforms
![Optical microscope image of ring resonator (loss ~0.5 dB/m) fabricated using the ultralow-loss, low-confinement silicon nitride platform.](/sites/default/files/rdgroup/image/2022-12/Ultralow-loss%20SiN.png)
Our ultralow-loss, low-confinement silicon nitride platform has a loss of 0.5 dB/m, allows for long delays, and has been used along with dual-polarization temperature stabilization to yield a 20-Hz linewidth long-term SBS laser. We are also developing a germanium-based platform for the midwave infrared and have shown losses on the order of 1 dB/cm and GHz-class filters. We maintain a standard silicon photonics process and component library. Custom fabrication platforms may be available upon request.
![Optical microscope image of a Germanium-based waveguides under development for the midwave Infrared wavelength range.](/sites/default/files/rdgroup/image/2022-12/Ge-based%20waveguides.png)