Photon spin processor for on-chip classical and quantum information systems

Researchers in the Dionne lab (D-Lab) at Stanford University have designed an on-chip, optical spin processor for classical and quantum information systems. The D-Lab chip-size spin processor efficiently generates one-handed circular polarized light regardless of excitation sources (e.g. light or electrical excitation), and detects both the circular polarization state and intensity of an incoming light at the same time.

The integrated nanophotonic platform (figure 1) includes a high-quality-factor (high-Q) chiral Si metasurface integrated with a light-emitting or absorbing thin-film. The high-Q chiral metasurface is made of periodically arranged silicon "meta-atoms" with a subwavelength thickness (i.e. 220 nm), Q over 2400, and a nearly 100-fold near-field electric field enhancement for one-handed circularly polarized light over the other. To demonstrate the photon spin processor for classical and quantum light sources, the D-Lab integrated the Si metasurface with a monolayer crystal MoSe₂, transition metal dichalcogenide (TMDC) film. The resulting processor, free of bulky birefringent crystals, can generate valley-selective emission at room temperature with a user-defined chirality. Importantly, the light emitter can be photoexcited or electrically excited. Compact chiral light generation for both classical and quantum systems can greatly improve multiplexing of data streams, increase speeds, lower latency, and increase data volume.

Stage of Development – Proof of Concept Prototype
Ongoing development includes expanding the number of spin processor pixels per chip, integrating the spin processor chip with an electrical circuit board, and packaging a prototype electro-optic device.