# Integrated Photonics for IoT, RoF, and Distributed Fog-Cloud Computing: A Comprehensive Review
## 7 Industry Implementations
Panels (b) and (c) provide detailed views of the laser-to-chip and fibre-to-chip interfaces, respectively, highlighting how PWBs adapt their geometry to match mode-field profiles for low-loss coupling, thereby eliminating the need for high-precision active alignment. National strategies in both the United States and Europe are accelerating the integration of photonic and electronic technologies to strengthen digital infrastructure and semiconductor independence. In the U.S., the CHIPS and Science Act and DARPA's LUMOs program support the development of CMOS-compatible PICs through funding, foundry access, and laser integration research [104; 109]. Meanwhile, Europe is advancing through Horizon Europe and PhotonHub initiatives, promoting open-access innovation, photonic-electronic co-design, and high-yield manufacturing via coordinated industry  
Figure 13: Concept and implementation of hybrid multi-chip modules (MCMs) through the 3D nano-printing of photonic wire bonds (PWBs), taken from [82]. **(a)** Illustration of an eight-channel transmitter, realized as a hybrid MCM comprising 3D-printed PWBs, shown in red. The PWBs efficiently connect photonic integrated circuits (PICs) realized on different integration platforms. **(b)** Interface between an InP laser chip and the silicon photonic transmitter chip, employing a horizontal cavity surface-emitting laser (HCSEL). **(c)** Fibre-to-chip interface, illustrating PWBs designed to match the larger mode-field diameter of single-mode fibres (SMFs). -academic consortia such as EPIC [103]. These efforts highlight a global push toward the development of scalable, power-efficient PIC ecosystems for data-intensive and latency-sensitive applications. To address these industrial bottlenecks, leading companies and research consortia are implementing a variety of strategies. For thermal sensitivity, thermal stabilization techniques such as micro-ring trimming, athermal design using cladding engineering, and feedback-controlled heaters have been deployed in commercial silicon photonics platforms [105]. For packaging and coupling challenges, advanced approaches like photonic wire bonding, self-aligning connectorized packaging, and 3D-printed optical interfaces are being developed to reduce insertion loss and improve alignment tolerance [110]. To combat manufacturing variability, foundries now increasingly use inverse design frameworks--the automated shape optimization of photonic devices with tolerance analysis--and apply digital tuning during the runtime using on-chip heaters or phase shifters [111]. On the testing side, AI-driven wafer inspection tools and integrated test photonics (e.g., built-in monitors and loophacks) are enabling scalable, real-time diagnostics [112]. Co-design strategies that align photonic and electronic components from the system architecture level are also gaining traction to simultaneously improve yield and performance. These efforts indicate a clear industrial pivot toward holistic PIC design workflows that integrate photonic layout, thermal control, testing hooks, and packaging early in the development cycle, accelerating the path toward reliable, high-volume deployment in distributed computing networks. Table 5 summarizes the main advantages of integrated photonics in Fog-Cloud computing.