Silicon photonic circuits gain light-emitting spots without losing electrical function

A simple manufacturing step added light-producing W centers to chips made on a commercial silicon-photonics platform.

Abstract editorial illustration accompanying the article: Silicon photonic circuits gain light-emitting spots without losing electrical function

Editorial illustration — not from the study.

The team used a back-end manufacturing process, applied after the main chip components had been fabricated, to create W centers in silicon-on-insulator photonic chips. With a 7.0 MeV implant energy, the chips produced W-center photoluminescence comparable to that achieved with earlier in-house fabrication methods.

Tests indicated that the emitted light came from the chip’s enclosed device layer, rather than from another part of the structure. The researchers also found that the added process preserved the electrical operation of the foundry-made components.

Light from silicon circuits

The researchers demonstrated W-center photoluminescence on chips fabricated using a mainstream commercial silicon-photonics platform. They created the light-emitting centers with a straightforward back-end-of-line process and achieved photoluminescence at a 7.0 MeV implant energy. The reported brightness was comparable to that of prior custom in-house processes. Measurements indicated that the emission came from the encapsulated silicon-on-insulator device layer, and electrical functionality was preserved.

Why this matters

Silicon’s indirect bandgap makes it difficult to build efficient light sources directly in standard silicon photonic circuits. Showing that light-emitting color centers can be added to commercial foundry-made chips without compromising their electrical operation supports the possibility of combining classical and quantum light sources with existing silicon photonic circuits. That compatibility is relevant to building more scalable photonic systems on a chip.

Evidence and caveats

This is an experimental demonstration using chips fabricated on a commercial CMOS-compatible silicon-photonics platform. The researchers used photoluminescence measurements to identify the light emission and electrical tests to assess whether the chip’s function was preserved. The abstract does not provide a numerical brightness value, report the performance of a complete integrated light source, or establish how the process would perform across large production runs.

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