Thirty Years of Sinking and Dawning, Silicon Photonics Development and Reflections

ICC News

The concept of silicon photonics was proposed as early as the early 1990s, but compared to the mature development and large-scale application of integrated circuits, its development has been relatively slow for more than 30 years after its birth, and the industrial ecosystem is still immature. The core reason is that there is no huge application scenario to drive. With the rapid development of cloud computing, big data, and artificial intelligence, society's demand for information acquisition and processing efficiency continues to rise, but Moore's Law is about to expire, and silicon photonics technology is becoming a definitive technology development trend by virtue of its outstanding advantages in terms of high throughput, high energy-efficiency ratio, ultra-low latency, and low cost.

Core view:

Currently, the silicon photonics industry is in the pre-expansion stage, and has achieved partial commercial success in optical communications, especially in the digital pass and short-range scenarios, and is gradually expanding into emerging application areas such as optical sensing and optical computing;.

Inter-chip optical interconnect and on-chip optical interconnect will be the first commercially successful application in the direction of arithmetic power enhancement.

In the field of silicon photonic process, optoelectronic packaging may be the fastest growing track, and co-packaged optics (CPO) is the most noteworthy technology direction.

Silicon photonics industry is based on silicon optical ecosystem, if we want to promote the trillions of industrial market landing, not only need the application side of the pull, but also the need for the construction of the underlying ecosystem, especially the construction of the process platform is crucial.

First，the silicon photonics industry overview

Silicon photonics technology is based on silicon and silicon-based substrate materials (such as SiGe/Si, SOI, etc.) as an optical medium, through the complementary metal-oxide semiconductor (CMOS)-compatible integrated circuit process to fabricate the corresponding photonic devices and optoelectronic devices (including silicon-based light-emitting devices, modulators, detectors, optical waveguide devices, etc.), and the use of these devices for photon launching, transmitting, detecting, and processing, in order to realise their practical applications in the fields of optical communication, optical sensing and optical computing. Such as the 1970s microelectronics technology in general, the silicon photonics industry is in the pre-expansion stage, the future is expected to become comparable to the huge scale of the integrated circuit industry, pulling trillions of dollars in the market. Because of this, such as Intel, IBM, Oracle, ZTE and other famous semiconductor companies and information technology companies, are investing a lot of human and financial resources to promote the industrialisation of silicon light. The landmark event is to focus on the scale effect of the foundry company GlobalFoundries (Grove Fonds, the industry referred to as "core") in March this year launched a silicon photonics platform Fotonix, so as to lay out the 90WG and 45CLO process nodes and packaging process, the platform Partners include three of the four top photonic transceiver suppliers, four of the five top networking companies, three of the four leading EDA and simulation companies, and some of the most promising photonics-based startups. Driven by both demand and resource investment, the silicon-optical industry has shown high growth in recent years, with the silicon-optical market set to grow from about $87 million in 2020 to about $1.1 billion in 2025, at a CAGR of 49 per cent, according to forecasts from leading semiconductor analyst Yole. At present, silicon light in optical communications, especially digital communication short distance scene has achieved local commercial success, is gradually expanding to optical sensing, optical computing and other emerging applications, especially optical sensing field of wearable health monitoring chip, with the release of health monitoring version of the Apple Watch, silicon light will be one after another to open up the market situation and maintain a high rate of growth.

Data sources：Silicon Photonics 2021 rep

Second, application Scenarios of Silicon Photonics

Optical communication field - the main application scenarios of silicon photonic chips. At present, the industry has basically established a series of silicon photonics communication product solutions for the data centre, fiber optic transmission, 5G bearer network, optical access and other markets, of which the data centre optical communication is the largest market for silicon photonics, and more than 40% of the internal data centre interconnections of Microsoft are based on the silicon photonics chip implementation. Data centre scenarios, CSPs and cloud providers (such as Facebook, Apple, Tencent, etc.) are shifting to large-scale data centres, Capex expenditures continue to rise to support the high bandwidth needs of customers, the communication rate is iterating from 100, 200G to 400G, 800G, 1.6T, 3.2T, and iterative cycle continues to shorten. In this context, the traditional pluggable optical modules in the price-performance ratio and power consumption has been "stretched to the limit", and highly integrated high-speed silicon photonics chip due to the potential price reduction space and power consumption has obvious advantages, has become a more superior option. Market choice is the best proof, the current 100G silicon photonic module has been a partial commercial success, although 400G, 800G silicon photonic module penetration will not have significant growth, but the industry consensus is that the communication rate of 1.6T stage silicon photonic module applications will be obvious quantity. Of course, still need to pay attention to the silicon photonics technology, especially the development of CPO packaging technology to bring the degree of price-performance enhancement. In addition, in the 5G bearer network market, 5G pre-transmission (telecom side of the optical module) is another market growth point of silicon photonics technology, Intel has been released for the 5G pre-transmission with an extended operating temperature range of 100G transceivers, support in the -40 ° C ~ 85 ° C operating temperature range through the single-mode optical fibre to achieve the 10km link. Although the pace of penetration is difficult to have a clear judgment, but the certainty of the silicon photonics trend is indisputable. Intel as a silicon photonics field of the leading companies, has already seized more than 40% of the market share of silicon photonics communication; Cisco, Marvell, Broadcom and other communication optical module head enterprises are based on the merger and acquisition mode of the layout of the silicon photonics module business; Domestic enterprises, Huawei (Haisi) Hisense, Hisense Broadband (Hisense), Innolignt (Innolignt), Hengtong Optoelectronics, Accelink (Accelink) and other optical module manufacturers have launched silicon-photonics communication modules, Innolignt set up a silicon-photonics business unit and the rapid development of Hengtong Optoelectronics and the United Kingdom Rockley (Rockley Photonics), the establishment of joint venture "Rockley Photonics (Rockley Photonics) to layout silicon photonics products. In addition, such as Xilian Optical Core, Sailor Optoelectronics, Xihe Technology, rain number of optical science and a large number of entrepreneurial enterprises have also flocked to the silicon photonics track, but is still waiting for the maturation of the market for high-rate communications applications, especially 1.6T and other high-speed rate of the optical module market is developing at a high rate. Optical sensing field - numerous application scenarios and rapid iteration, silicon photonics development potential. At this stage, silicon photonics chips for LIDAR for autonomous driving and silicon photonics chips for consumer health monitoring and diagnosis will be important growth points. Automated driving has been internationally recognised as one of the key directions for future development, and LIDAR-based automated driving solutions ecological more complete, the essence lies in the redundancy design is critical, and LIDAR can sense the long-tail problem, but the cost-effective and vehicle regulation requirements limit the pace of LIDAR in-vehicle applications. After market screening, all-solid-state LiDAR based on silicon photonics OPA+FMCW solution has become the accepted end game solution in both academia and industry, with huge market potential. Because of this, silicon photonics-based LiDAR startups such as Lowepro Technology and Moore Core Optics in China are highly favoured by capital. In the field of biosensing, silicon photonics integration solutions gradually in a number of scenarios, such as Surfix based on silicon photonics integration solutions to achieve fast and high-precision nucleic acid detection, Aryballe developed a miniature silicon photonics artificial nose as a means of identifying the smell of "fingerprints" and so on, and is now recognised as the most promising market is a wearable device.

It is reported that in 2022 or 2023, Apple and the British Rockley company (Rockley Photonics) will cooperate with the launch of the integrated on-chip spectrometer Apple Watch. in addition, Amazon, Microsoft, Facebook, Google, Tencent and so on have to enter the game, the domestic has also emerged a lot of on-chip spectrometer entrepreneurship Yole judgement, with the release of health monitoring version of Apple Watch, the optical sensing chip market for health monitoring will maintain high growth. In the future, silicon photonic biosensing chips can also be widely used in low-cost, small-sized medical devices, and is expected to exceed the market size of silicon photonic communications in 2026.

With the failure of Moore's Law, optical computing and silicon photonics concepts are being focused on at the same time. Currently, electronic computing faces three major bottlenecks of storage and calculation, I/O, and power consumption, which gradually makes it difficult to meet the demand for ultra-high-speed, low-latency mass data processing. Optical computing, based on the natural advantages of photons as bosons in transmission and multi-dimensional information processing advantages, has become the ideal choice for the next generation of computing paradigm, while silicon photonic integration is the basic premise for the commercialisation of optical computing. At present, the attention of the optical computing segmentation direction is mainly for the silicon photon based neural network AI processor chip and optical interconnect, it should be noted that the optical interconnect is based on the principle of optical communication, but to solve the problem of optical computing I/O, so it is temporarily attributed to the field of optical computing. Restricted by the size of the calculation, calculation accuracy and algorithm ecology and other aspects of the limitations, photoelectric fusion computing is still the main calculation scheme, but also has not yet industrialised applications.

In the short term, inter-chip optical interconnect and on-chip optical interconnect will be the first commercially successful application in the direction of arithmetic power enhancement. Currently, Intel data centre has adopted inter-chip optical interconnect to improve computing performance, and NVIDIA will also cooperate with Ayar Labs to apply optical I/O to AI/HPC architecture.Ayar Lab is a major startup in the optical interconnect track, which has raised more than $200 million in ongoing financing, with a $1,137.5 million valuation in the B-round, and an estimated $2 billion valuation in the C-round, with investors including Intel, NVIDIA, and NVIDIA. including Intel, NVIDIA, Global Foundries and others. It is reported that optical computing startup Xi Zhi Technology will also launch optical interconnect-related products. In addition, the essence of optical quantum computing also belongs to the category of optical computing, but the optical quantum computing landing cycle is optimistically expected to still take about 5 to 10 years, the short term can not pull the development of silicon photonics industry.

Third, the development of silicon photonics ecology

Data source: Silicon Photonics 2021 report, Yole

Silicon photonics industry is a general trend, application scenarios side of the market space potential is exciting, but return to the nature of manufacturing, silicon photonics industry is based on silicon photonics ecology, if we want to promote the trillion industry market landing, not only need to application side of the pull, but also need to be more of the construction of the underlying process ecology. At present, the key issues facing the silicon photonics industry, lies in the process platform is not mature, silicon active device is difficult to achieve as well as nano-size silicon photonics technology path has not yet converged, etc., especially the construction of the process platform is crucial. In contrast to the development history of the integrated circuit industry, the optimisation of semiconductor processes has always accompanied the development of its various important milestones. Therefore, the layout of the silicon photonics process platform is the key to the continued penetration of silicon photonics applications. The broad silicon photonics process platform includes design tools, processing, packaging and other processes throughout the chain. The construction of process ecology will be the long-term goal of industrial development, such as silicon photonics design tools have not been unified, semiconductor CMOS process can not support large-scale integration, silicon photonics chip differentiated design to increase the difficulty of process monitoring and optimisation, etc., all need more resources. China has laid out a number of processes and mass production lines, mainly for the Chinese Academy of Sciences Institute of Microelectronics silicon photonics process platform, the Chinese Academy of Sciences Institute of Microsystems silicon photonics process platform, Chongqing United Microelectronics Centre, in addition to commercial foundries such as Yandong, SMIC has also been in the layout of the silicon photonics process research and development, to accelerate the process of silicon photonics mass production. We judge that optoelectronic packaging or will be the fastest growing track, and co-packaged optics (CPO) is the most noteworthy technology direction. According to foreign market research organisation CIR, by 2027, the co-packaged optics (CPO) market revenue will reach $5.4 billion. Throughout the silicon photonics industry ecosystem, from process to application, under the continuous strong investment of leading enterprises such as Intel, Cisco, Juniper, etc., the silicon photonics whole industrial chain has been continuously improved, and technical standards have been formed one after another, which has gradually transformed from an academic research-driven to a market demand-driven virtuous cycle. Under the vigorous promotion of the layout of the academic and industrial circles, silicon photonics is expected to develop into a huge industry comparable to integrated circuits in the next 20~30 years. Domestically, more resources need to be invested in the layout of the underlying process ecology, and to support the silicon photonics design companies to develop applications, with a view to building a competitive advantage in the silicon photonics track, to achieve the chip in the field of curved-track overtaking.

From ICCSZ Reprinted

http://www.iccsz.com//Site/CN/News/2022/09/30/20220930094936610923.htm