All You Need To Know About The Emerging Star Of Optical Chip

As the demand for higher speed and bandwidth increases, optical modules, which are essential for optical-electrical conversion, have experienced explosive growth. Consequently, optical chips, a crucial component of these modules, have also come into the spotlight.

What is an Optical Chip?

An optical chip, also known as a photonic chip, is an integrated circuit that uses light waves for information transmission and data processing. Typically made from compound semiconductor materials such as InP and GaAs, it achieves optical-electrical signal conversion through the generation and absorption of photons during internal energy level transitions.

These chips rely on dielectric waveguides in integrated optics or silicon photonics to transmit guided light signals. They integrate the modulation, transmission, and demodulation of optical and electrical signals on a single substrate or chip. Compared to traditional electronic chips, photonic chips use light instead of electrical currents to transmit data. This results in high density, high speed, and low power consumption.

In short, optical chips are fundamental components for converting optical signals to electrical signals. Their performance determines the transmission efficiency of optical communication systems.

Development Status of Optical Chip

The development of optical chips dates back to 1969 when Bell Labs in the United States proposed the concept of integrated optics. However, due to technological and commercial challenges, significant progress didn’t occur until the early 21st century. At that time, companies like Intel and IBM, along with academic institutions, began focusing on silicon chip optical signal transmission technology. Their aim was to replace data circuits between chips with optical pathways.

Today, pure photonic devices can function as independent modules. However, they still face limitations. Controlling optical switches is challenging, and these devices can’t act as storage units like electronic devices. As a result, pure photonic devices cannot fully handle information processing on their own and still need electronic devices. Therefore, a purely “photonic chip” is still a concept and not yet a practical system. The current “photonic chips” are actually optoelectronic hybrid chips that integrate photonic devices or functions. They still struggle with integrating high-density light sources and low-loss, high-speed electro-optic modulators.

Despite being in the early stages, photonic integrated circuits are set to become the mainstream in optical device development. The future of photonic chips will involve integration with mature electronic chip technology. Using advanced manufacturing processes and modular techniques from electronic chips, silicon photonics, which combines the strengths of both photonics and electronics, will lead the way forward.

From a market perspective, the United States was the first country to start and excel in the field of silicon photonics. Early on, associations were established to guide capital and various forces into the optoelectronics field. Singapore’s IME is also one of the early platforms for silicon photonics processes, contributing significantly to the industry’s development.

Currently, the global optical chip industry chain has gradually matured, with representative companies involved in every stage from basic research to manufacturing processes and commercial applications. Companies like Intel, Cisco, and NVIDIA dominate the shipment volumes of silicon optical chips and modules, becoming leaders in the industry.

Applications of Optical Chip

High-speed data processing and transmission are the pillars of modern computing systems. Optical chips provide a crucial platform for integrating information transmission and computation, significantly reducing the cost, complexity, and power consumption of connections. As optical chip technology evolves, large cloud computing providers and enterprise customers are transitioning from lower-speed to higher-speed modules. Consequently, optical chips are increasingly being used in high-performance computing and data centers. They are also becoming more prevalent in the telecommunications market.

  • High-performance computing

In high-performance computing, optical chips offer high speed and low energy consumption, greatly enhancing computing efficiency and processing speed. This is particularly important for handling large, complex algorithms and models, which are vital in fields such as scientific research, climate modeling, and biotechnology.

  • Data center

Data centers are the backbone for data and data processing. The construction of data centers provides the necessary equipment support for large-scale data storage, exchange, and application needs. The larger the data flow, the more complex the data processing methods, making data centers increasingly important. Currently, the global solution to handling data flow is the construction of large-scale data centers. Therefore, the global construction of these large-scale data centers will be a significant driving force for the optical module market, thereby driving the demand for optical chips.

  • Telecommunications

Currently, countries around the world are striving to meet the demands of 5G networks. Compared to 4G, 5G uses higher frequencies, which significantly weakens its coverage capability. As a result, the number of base stations required to cover the same area with 5G will undoubtedly exceed that of 4G. The communication services in the 5G era have also created a huge demand for optical chips and optical modules.

Future Trends in Optical Chip

As the internet industry develops, the demand for optical modules is gradually trending towards miniaturization and high performance. The future technological direction of optical chips can be embodied in silicon photonics technology.

Silicon photonics technology is a new generation of technology that develops and integrates optical devices on silicon and silicon-based substrates using CMOS processes. Its core concept is to use laser beams instead of electronic signals for data transmission.

Silicon photonic modules and regular optical modules use different chips, leading to various differences in their product parameters, even at the same speed and in the same scenario.

QDD-400G-DR4-SQDD-400G-DR4-S SiPh-Based
Center Wavelength1310nm1310nm
ConnectorMTP/MPO-8MTP/MPO-12(8 of the 12 Fibers Used)MTP/MPO-8MTP/MPO-12(8 of the 12 Fibers Used)
Modulation8x 50G PAM48x 50G PAM4
DSPInphi 7nm DSPBroadcom 7nm DSP
Transmitter TypeEMLDFB
Packaging TechnologyCOBCOB
ProtocolsIEEE 802.3bs, QSFP-DD CMIS Rev 4.0, QSFP-DD MSA HW Rev 5.1IEEE 802.3bs, QSFP-DD MSA, CMIS 4.1
ApplicationData Center800G to 2x400G Breakout400G to 4x100G BreakoutData Center800G to 2x400G Breakout400G to 4x100G Breakout

Since regular optical module technology is more mature and requires lower deployment environment standards, silicon photonic modules will be challenging to scale up in the market in the short term.

Nonetheless, with the further expansion of 5G network construction and the growing demand for data transmission, the silicon photonic module industry is expected to enter a rapid development phase.

Summary

To summarize, optical chips have become a focal point in the industry and one of the most lucrative areas for venture capital. Exploring new technologies has become a key task in the semiconductor field. The application of optical chips will significantly impact the performance of optical modules and has the potential to reshape the existing optical module industry chain.