# Integrated Photonics for IoT, RoF, and Distributed Fog-Cloud Computing: A Comprehensive Review
## 7 Industry Implementations
\begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline
**Topic** & **State of the Art** & **PIC Research Opportunities** \\ \hline Integration of photonics components & Flip-chip bonding and monolithic integration techniques enable dense photonic-electronic modules for Fog/Cloud applications [49, 53, 54]. & Develop scalable co-packaging and bonding techniques for heterogeneous material integration. \\ \hline Electronic integration & TSVs, 3D stacking, and CMOS compatibility enable high-speed interfacing with low parasitics [49, 53]. & Manufacturing of 1 nm transistors and moving into the 0.1 nm region. Optimize co-design strategies for reducing interface loss and enhancing signal integrity. \\ \hline Laser transmitter & MACOM’s L-PIC platform and Ranovus’ Odin integrate lasers on PICs for AI/data center use [62, 64]. & Enhance monolithic laser integration for reliable, low-threshold, and tunable light sources. \\ \hline Semiconductor optical amplifiers & InP-based integration and hybrid platforms extend amplification capabilities [61]. & Improve hybrid integration methods to enable low-noise, high-gain on-chip amplification. \\ \hline High-Speed Optical Interconnects & Intel OCI, Cisco OSFP-XD, IBM CPO, NVIDIA Quantum-X800, and Maxwell light engine demonstrate high-speed photonic links [3, 55, 56, 57, 60]. & Reduce energy consumption and latency while improving bandwidth density at rack and chip scales. \\ \hline Energy-Efficiency & Integrated architectures reduce parasitic loss and enable low energy per bit [46, 51, 52]. & Develop energy-aware PIC design tools and materials with lower thermal and electrical losses. \\ \hline Compactness and Scalability & PICs integrate optical functions in compact chips, reducing footprint and improving scalability [46, 47, 48]. & Advance high-density PIC layouts and integration methods for future ultra-compact modules. \\ \hline Optical Switching and Routing & All-optical switching and routing eliminate O/E conversion, reduce latency, and increase agility [66, 67, 68, 71, 72]. & Implement programmable optical networks with tunable components for dynamic traffic management. \\ \hline Wavelength Division Multiplexing & Integrated WDM multiplexers/demultiplexers support dense, efficient transmission [73, 74]. & Increase WDM channel count and reduce crosstalk through improved filtering and thermal tuning. \\ \hline Coherent Optics & PICs support QAM, coherent detection, and UDWDM for long-range, high-capacity links [74, 78, 79, 80, 81]. & Advance DSP and integration of polarization and phase management for coherent systems. \\ \hline Quantum and Advanced Computing & PICs integrate quantum sources, modulators, and detectors for scalable quantum and neuromorphic computing [67, 83, 84, 85, 86]. & Co-design photonic platforms with quantum hardware for scalable Fog–Cloud quantum integration. \\ \hline \end{tabular}
\end{table} 
Table 4: Summary of PIC research topics. multi-haul WDM systems integrated into advanced line systems [88], as well as deployment with partners like CoreWeave to support an AI-optimized Cloud infrastructure [89]. These platforms are designed to deliver high-capacity, energy-efficient, and latency-aware connectivity across hyperscale data centers and distributed Fog nodes. In parallel, research by [PERSON] et al. has demonstrated the use of integrated photonic digital-to-analog converters (DACs) for on-chip high-speed optical signal generation, addressing electronic bottlenecks and improving throughput, latency, and spectral efficiency in wide-area Fog-Cloud networks [90]. Nokia is further investing in programmable photonics for software-defined optical networks and has presented silicon photonic switches capable of rapid reconfiguration [91]. Fujitsu, on the other hand, is focusing on integrated RoF platforms using PICs to simplify front-haul deployment in dense urban environments, a key asset for edge-based 5G/6G architectures [92].