As an entrepreneur with 22 years of experience in the optical communications industry, I have been deeply involved in precision optical manufacturing and design, as well as fiber optic components, for many years. I have long wanted to organize my thoughts on those “silently shining” optical lenses in optical communications. Though they seem tiny, they serve as the “critical bridge” for optical signal transmission.
Today, I want to talk about lenses for optical communications in plain, easy-to-understand language. Whether you are a colleague in the industry or a friend from outside the field, you will be able to understand and relate.
First, Some Industry Old History
In the early years, those of us in the industry were accustomed to dividing the entire optical communications sector into two major categories: active optical communications (simply put, involving electricity and optical chips, capable of actively converting optical signals) and passive optical communications (requiring no active power supply, mainly performing transmission and distribution of optical signals). Lenses are indispensable in both categories, but the types of lenses used, their characteristics, and even market demands differ significantly.
① The Old Two in Passive Optical Communications: C-LENS and GRIN LENS
In the passive optical communications field, the most common types are C-LENS (ball lens) and GRIN LENS (gradient-index lens). Over the years, market demand for these two types of lenses has been in a state of “ebb and flow” – sometimes demand is higher for one, sometimes the other accounts for a larger share.
In simple terms, they are mainly used in the fiber-to-the-home connections, campus fiber cabling, and operator fiber cross-connect cabinets we encounter daily. For example, home broadband fiber interfaces and the fiber distribution equipment in residential areas may contain these two types of lenses. They are responsible for accurately conducting and distributing the optical signals in the fiber, ensuring stable signals for internet browsing and TV viewing at home. In industry terminology, these are called access networks, backbone networks, etc.
② The Active Optical Communications Field: The Main Battlefield for Lenses
Let’s focus on lenses in the active optical communications field, where we also include data centers (because data centers use a large number of optical-electronic chips, essentially falling under the scope of active optical communications). In recent years, the explosion in popularity of data centers has directly driven a surge in demand for optical-electronic chips, even leading to shortages. This热度 has also spread to lenses, making some lens products scarce.
However, as a practitioner with 22 years of deep industry experience, I look at this more rationally: there are too many types of lenses in optical communications. Different lenses have different production capacities and different application scenarios, so market demand naturally varies significantly. Not all lenses are “hard to find and in high demand.”
First Type: Silicon Lenses – The King of Production Capacity
Currently, these have the largest production capacity. Based on my understanding, the annual production capacity of silicon lenses is at least over 500 million units. The leading companies in the market mainly include SuNa, Luohe Leixin, HuaTian HuiChuang, and Switzerland’s Arteris. The manufacturing process is somewhat similar to the semiconductor industry, mainly lithography and micro/nano machining etching processes, offering high precision and mass production capability – this is key to their dominance in the large market.
Their core application scenario is today’s booming data centers. For example, behind our daily activities of watching videos, sending messages, and storing files, data centers are needed to store and transmit data. Silicon lenses are installed in the high-speed optical modules within data centers, responsible for collimating, focusing, and coupling the light from optical chips.
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Second Type: Glass Aspheric Lenses – The Broadest Application
Many manufacturers are making this type of lens: internationally, there are Panasonic, Alps, and Korea Micro Phoenix; domestically, there are G-Tech, Hobbite, and others. The core process is molding technology (continuous molding or multi-station molding). Although mold costs are relatively high, the advantages are good batch-to-batch consistency and high precision, making them suitable for large-scale applications.
Their application scenarios are even broader. Besides medium-to-high-speed optical modules for data centers, they are also used in optical communication equipment for 5G base stations – for example, the 5G signal on our phones needs to be relayed by base stations, and the optical modules within those base stations use glass aspheric lenses to ensure long-distance, high-quality transmission of 5G signals. Additionally, fields like industrial lasers and medical lasers are inseparable from them because their precision meets the demanding beam requirements of high-end equipment for collimation, coupling, and focusing beams.
I must mention Hobbite here in China. Their non-isothermal molding technology has significant advantages. It enables mass production similar to silicon lenses and can produce flat molded, multi-matrix, multi-channel products widely used in popular fields like CPO, NPO, OCS, and pluggable optical modules.
Furthermore, there are many types of glass lenses, such as bare aspheric lenses (available in both round and square shapes), aspheric lenses with metal rings, CAP aspheric lenses, and matrix aspheric lens arrays, each corresponding to different application scenarios.
Third Type: C-LENS – The Former Big Brother
C-LENS lenses are manufactured purely through cold processing. Their production speed ramps up slowly and relies mainly on manual labor plus semi-automated operations, unable to achieve full automation. Many old-timers in the industry may remember: before silicon lenses became widespread around 2019, almost all optical modules used C-LENS – they were inexpensive, customizable, and saved installation space, offering high cost-effectiveness.
But later, as demand for optical modules exploded, the production capacity of C-LENS could not keep up, and they were largely replaced by silicon lenses. This also shows how pragmatic and forward-looking our optical module and optical equipment industry is – we use whatever is suitable.
Currently, C-LENS has not completely exited the market. They are mainly used in some medium-to-low speed, small-batch optical modules, such as fiber optic transmission modules for surveillance equipment, fiber optic interfaces for small routers, and some customized industrial optical communication equipment. These scenarios have less demanding capacity requirements and prioritize cost-effectiveness more.
Who Fills the Gaps of Silicon Lenses?
However, silicon lenses also have their limitations, such as being relatively limited in wavelength selectivity. For example, at the commonly used wavelength of 850nm, Hobbite’s aspheric lens array can effectively complement silicon lenses. But in large-scale applications of SR modules (short-reach optical modules), the market is actually dominated by plastic lenses.
Besides these, many CAP-sized ball lenses occupy over 80% of the market share in low-speed TO-CAN devices – truly the “low-key主力.” You might not be familiar with TO-CAN devices; they are often used as core components in fiber optic transceivers and low-speed optical modems. For example, older home fiber modems or small office fiber optic transceivers use these CAP ball lenses, responsible for simple optical signal transmission and reception, stable and inexpensive.
Fourth Type: Plastic Lenses – The “King of Cost-Effectiveness” for Short Distances
Plastic lenses have “won” in the SR module field for several reasons. On one hand, there is a strong demand due to the large-scale deployment of SR modules. On the other hand, plastic lenses themselves have advantages – low cost, light weight, and suitability for mass production. Representative companies include Taiwan’s Ho Cheng, Foxconn, and Dongguan Blue Light. The manufacturing process is also mold-based, similar to the molding process for glass aspheric lenses, but with lower costs, making it more suitable for widespread adoption.
They are mainly used for short-distance optical transmission, such as short-distance connections within data centers (optical signal transmission between different servers in a server room), fiber optic connections for local area networks in office buildings, and short-distance fiber transmission between home fiber modems and routers. These scenarios do not require long-distance transmission and are more cost-sensitive. Plastic lenses meet these needs well, and their light weight allows equipment to be made smaller.
Final Thoughts
These are the main types of lenses in the optical communications field. From the perspectives of production scale, application scenario selection, and technology development paths, these seemingly tiny lenses actually occupy a pivotal position in the optical communications industry chain – without them, optical signals could not be transmitted efficiently and stably, and the scenarios we take for granted, like data centers and fiber optic communications, could not function properly.
As a 22-year industry veteran, watching lenses go from a single category to a diverse range, and from relying on imports to the rise of domestic companies, I truly feel quite emotional. The industry is progressing, and we are growing as well.
If there are any omissions, please feel free to correct and supplement!
Hobbite has focused on the optical communications field for 11 years, mainly providing: optical design, precision optical processing (spherical/planar/coating), non-isothermal molding, and optical component OEM. We have a team of 260 people. Welcome to contact us for guidance! Email: [email protected]
