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Abstract—We experimentally demonstrate normal-incidence grating couplers designed using topology optimization to couple into multi-core fiber. The insertion loss of the polarizing and polarization demultiplexing gratings was –5.5 dB and –7.7 dB, which is within 0.8 dB of the performance obtained using a fiber array
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Multi-layer inverse design of vertical grating couplers for high-density, commercial foundry interconnects
Density-based topology optimization is used to design large-scale, multi-layer grating couplers that comply with commercial foundry fabrication constraints while simultaneously providing beam profiles that efficiently couple to a single-mode optical fiber without additional optics. Specifically, we describe the design process and experimentally demonstrate both single- and dual-polarization grating couplers that couple at normal incidence (0° from the normal) with low backreflections (-13.7 dB and -15.4 dB at the center wavelength), broad 3 dB bandwidths (75 nm and 89 nm), and standard coupling efficiencies (-4.7 dB and -7.0 dB). The dual-polarization grating couplers exhibit over 30 dB of polarization extinction across the entire band. The devices were fabricated on the GlobalFoundries 45CLO CMOS platform and characterized across three separate wafers. This new design approach produces distinct features for multiple foundry layers and yields emitters with arbitrary, user-specified far-field profiles.
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- Award ID(s):
- 2052808
- PAR ID:
- 10369437
- Publisher / Repository:
- Optical Society of America
- Date Published:
- Journal Name:
- Optics Express
- Volume:
- 30
- Issue:
- 17
- ISSN:
- 1094-4087; OPEXFF
- Format(s):
- Medium: X Size: Article No. 31058
- Size(s):
- Article No. 31058
- Sponsoring Org:
- National Science Foundation
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