optical

**Optical Interposer** is **silicon-based optical routing layer with integrated modulators and detectors for photonic chip-to-chip communication** — optical routing substrate. **Architecture** silicon waveguides route signals; integrated electro-optic modulators; photodiodes detect. **Waveguides** sub-wavelength (~400×200 nm) silicon guides enable single-mode, compact routing. **Modulators** Mach-Zehnder or microring resonators encode signals. **Photodiodes** Ge or Si detectors on same substrate. **Light Source** external laser (telecom) or heterogeneous III-V bonded source. **Coupling** efficient input/output coupling via grating couplers or butt-coupling. **Bandwidth** >25 GHz per channel demonstrated. **Channels** WDM: 4-16 wavelengths tested. **Power** sub-pJ/bit achievable for optical links. **Eye Diagram** high-speed testing validates signal quality. **BER** bit-error-rate testing measures reliability. **Wavelength** 1310/1550 nm (telecom) or 850 nm (data-center). **Thermo-Optic** refractive index varies with temperature. Active tuning compensates. **Crosstalk** waveguide spacing reduces coupling between channels. **Routing Density** thousands of channels possible. **Integration** optical interposer + electrical logic/memory. Tight integration. **Chiplet Communication** optical links between chiplets enable new architectures. **Prototypes** published >100 Gbps/channel, >1 Tbps aggregate. **Standards** JEDEC developing chiplet optical interfaces. **Reliability** long-term reliability of optical components unproven. **Optical interposers enable revolutionary bandwidth** for heterogeneous systems.