Summary of Key Points
The competition in AI computing power has shifted from the performance comparison of individual GPUs to the collaborative capabilities of clusters. Optical chips, especially those using VCSEL (Vertical-Cavity Surface-Emitting Laser) technology, have become crucial for enabling efficient interconnection between GPUs. Chang Ruihua, a foreign academician of the Chinese Academy of Engineering, believes that there will inevitably emerge giants in the field of optical chips similar to NVIDIA, and Chinese companies should " blaze their own trail" rather than simply following in their footsteps. The integration of optics and electronics is the future direction, with new product forms such as optical engines set to rise rapidly. Although the industry experiences short-term fluctuations, the long-term trend is clear.
1. AI Computing Power Is Not Just About GPUs; Interconnection Capability Is the Next Battlefield
In the past, strong AI computing power was associated with a large number of high-performance GPUs. However, training large models now requires hundreds or even thousands of GPUs working together—similar to hundreds of people moving a heavy box; having many people is useless if they don't coordinate effectively. This leads to a bottleneck in data transmission between GPUs. Copper wires lose significant signal strength over short distances (just a few centimeters), much like how a voice becomes blurred when it travels far. NVIDIA's latest NVL72 rack system places switching devices close to the GPUs, and Huawei has developed 1024-card clusters to reduce transmission distances. Chang Ruihua emphasizes that the next competition in AI computing power will largely revolve around interconnection capabilities, and optical chips are the perfect solution because they allow for fast and low-loss signal transmission, enabling smoother communication between GPUs.
2. Three Optical Chip Technologies: Why Is VCSEL the Favorite?
There are three current technologies for short-range optical interconnection in AI, each with its advantages and disadvantages:
- Silicon Photonics EML (Electro-Mechanical-Lighting): Extremely fast per channel but limited in number of channels and expensive.
- Micro LED: Can integrate many channels but has slow per-channel speeds and is incompatible with existing fiber optics.
- VCSEL: Balances high speed with the ability to form two-dimensional arrays, solving the issues of both low integration efficiency and high-speed transmission challenges.
Chang Ruihua's team at Bosun Optoelectronics uses a "flip-chip" design, placing the VCSEL electrodes on the back of the chip, which not only solves heat dissipation problems but also allows for more channels to be integrated. They have already sold over 6 million high-speed VCSELs.
3. Optical Chips Follow Their Own Growth Patterns
Optical chips do not follow Moore's Law (doubling performance every 18 months) like electronic chips; instead, they have their own expansion patterns. Industries like LEDs and optical communications find parameters (such as brightness or bandwidth) that can be continuously improved, driving progress. Traditional pluggable optical modules will not disappear due to their maturity and ease of maintenance, but "optical engines" will emerge—smaller, GPU-embedded modules that can convert data into light more efficiently. She believes that it's not about optics replacing electronics entirely but about dividing tasks: electronics handle logic, storage, and control (their strengths), while optics excel in high-speed transmission and parallel processing.
4. Chinese Optical Chips Should "Blaze Their Own Trail"; Why Is Shenzhen the Perfect Location?
When asked whether Chinese companies should pursue imitation or innovation, Chang Ruihua firmly advocates for the latter. She settled in Shenzhen in 2021 and joined the Chinese University of Hong Kong, Shenzhen in 2023, choosing this city because it fosters a spirit of hard work and innovation and is open to new technologies. Bosun Optoelectronics has been able to rapidly develop its technology in Shenzhen. She cites her own motivation for researching VCSELs for decades: "Even if others say it's impossible, I want to give it another try." This exploratory spirit is key to breakthroughs in China's optical chip industry.
5. The Industry Has Fluctuations but a Bright Long-Term Future; Don't Worry About Overcapacity
Some worry about potential overcapacity in the optical communication industry, but Chang Ruihua points out that all industries experience cycles, with a clear long-term trend of increasing bandwidth demand and the expansion of optical interconnection to shorter distances (e.g., from data centers to directly adjacent chips). Short-term fluctuations are like waves; companies need to learn how to navigate these cycles—accumulating technology during downturns and seizing opportunities during peaks. She concludes that the future of optical chips is promising, and by following the trends, Chinese companies can gain a share in the AI computing power competition.
This news highlights that in the AI era, optical chips represent an under-the-radar opportunity, and Chinese companies have the potential to become global leaders in this field.