3KMLink breaks through the technical barrier of high price of optical fiber slip rings

3KMLink breaks through the technical barrier of high price of optical fiber slip rings

Conductive slip rings cannot meet the development needs of high-end information technology

With the development of science and technology, the requirements for high-speed signal transmission are getting higher and higher. For example, our home network has changed from the previous 2M, 4M, 10M network cable transmission to optical fiber transmission of 100M, 100M, and 10M; another example is the mobile phone pixels we use every day. From the previous 300,000, 500,000 to 2,000,000, 5,000,000 and now 20 million or even hundreds of millions of pixels; people's pursuit of quality of life is getting higher and higher, and industrial intelligent manufacturing is also unwilling to lag behind, and traditional conductive slip rings have become more and more The more it can not meet the needs of high-speed signal transmission.

Defects of high-speed signal transmission of traditional conductive slip rings:

1. The structure limits the upper limit of the transmission rate of traditional conductive slip rings;

2. The network transmission stability of the hat-type slip ring single brush wire contact network used in the security ball machine is poor;

3. The signal is easily interfered, and the anti-electromagnetic interference ability is poor;

4. There are many loops and large size;

5. The traditional conductive slip ring relies on metal contact friction, and the service life is limited;

Since the high-speed signal transmission of the conductive slip ring is limited by its own technical defects, it can no longer meet the development needs of the information technology industry, so there is a fiber optic slip ring. Mega, exascale, exascale and even higher specialized market segments.

Advantages and disadvantages of traditional optical fiber slip ring market application

Optical fiber slip ring market application areas:

1. Application of optical fiber slip ring in security high-speed ball machine;

2. The application of optical fiber slip rings in optoelectronic pods;

3. The application of optical fiber slip rings in deep-sea detection and cabling equipment;

4. Application of optical fiber slip ring in robot;

5. Application of optical fiber slip ring in testing equipment;

6. Application of optical fiber slip ring in OCT and flight simulator;

7. Application of optical fiber slip ring in wind energy and helicopter;

......etc.

The application fields of the optical fiber slip ring market are very many and very extensive, and they make up for the defects of the conductive slip ring. So why is there not much market usage at present? In fact, this is because the price of optical fiber slip rings is too high. At present, the price of single-channel optical fiber slip rings in the market is more than 2,000 yuan, so many projects are stopped by the price of optical fiber slip rings. Taking the security monitoring products with a market of hundreds of billions, the price of a high-end monitoring dome is about 10,000 yuan. No matter how important the role of the slip ring is, the manufacturer cannot afford such a large price proportion.

Analysis of the reasons for the high price of optical fiber slip rings

Technical difficulty and high manufacturing cost are the two main reasons for the high price of optical fiber slip rings.

Optical fiber slip rings can be divided into two technical structures: collimation (non-contact free space axis alignment) and coupling (using couplant) according to the optical connection technology. Both have their own advantages and disadvantages. In the early days, optical coupling using couplant connection The efficiency is lower than the collimated connection, and the optical coupling efficiency of the two technologies is now relatively close. Ten years ago, professional companies and research institutes in Europe and the United States achieved a fiber coupling efficiency of 75-80%, while that in China was below 75%. With the development of technology, the optical coupling efficiency of single-mode fiber has increased to 86%, and the optical coupling efficiency of multi-mode fiber has reached 92%. That is to say, the optical coupling efficiency has improved by less than 10% over a decade.

There are many and complex factors that determine the optical coupling efficiency of optical fibers, including light sources, materials, design, technical principles, manufacturing processes, etc., each of which is a professional discipline. Therefore, I will introduce it here with the help of one of the simplified images (if you need to know more and more professional, you can pay attention to the public account of the three-kilometer connection slip ring), so that everyone can understand it better. The diameter of the end face of the fiber core is only 5-9 μm (comparable to the thickness of a hair). It is necessary to ensure that after the optical signal is emitted from the end face of such an optical fiber, it is irradiated to another fiber along the axis at a predetermined angle of incidence. On the end face of the fiber core, its precision and operation difficulty can be imagined. Moreover, relative to the coupling spot, the receiving area of the fiber end face is too small, so that a slight position shift or a change in the incident angle will cause a rapid drop in the coupling efficiency.

What's more, after the beam with the best coherence is collimated, its outer diameter is not a set of balanced straight lines. In the actual process, it will converge to form a beam waist (ie, the minimum beam diameter, Beam Waist Diameter), and then diverge at the same speed. , the divergence speed increases after reaching a certain point. As shown below:

To maximize fiber coupling efficiency, the incident light must be an axially propagating Gaussian beam with a beam waist at the fiber end face and a waist diameter equal to the core receiving face diameter (MFD).

Since the optical fiber slip ring is in a state of unrestricted 360° rotation at a speed of hundreds or even thousands of revolutions per minute, it is necessary to ensure the stability and reliability of optical transmission during high-speed rotation, that is, the fluctuation of insertion loss. The value is guaranteed to be within 0.5db, and there is no flash or packet loss in data transmission. Its technical requirements have long exceeded human imagination.

In the production process of traditional optical fiber slip rings, the difficulty is that the optical axis center of the optical fiber and the geometric center of the rotating shaft must be highly coincident, and the optical axis centers of the collimators at both ends must be highly parallel, which requires a large number of micron-level precision tooling. The assembly effect is easily affected by human factors, and the production personnel are required to be skilled in technology and have very rich production experience. A skilled technician can achieve a fine adjustment of less than 0.001 turns when screwing a screw. Even so, it still takes 5-20 minutes for the alignment and calibration section of only one fiber optic slip ring. The low production efficiency and low product yield of traditional optical fiber slip rings are the biggest reasons for the high manufacturing cost of optical fiber slip rings.

Break through the technical barriers of high price of traditional optical fiber slip rings

The high-priced technical barriers of optical fiber slip rings have existed for a long time, because foreign manufacturers are willing to harvest the high-priced technical barriers established by themselves. Domestic manufacturers have followed the practice of imitating design and lacked innovation motivation. In order to break the high-priced technical barriers of traditional fiber optic slip rings and open up a broader market for fiber optic slip rings, Sankilun, which has nearly 20 years of experience in optical communication and laser technology applications, established a special research and development team in 2020. After more than one year of unremitting efforts, after repeated design, verification, overthrow and summary, a new type of optical fiber slip ring series was finally successfully developed in 2021, breaking the technical barrier of high price of optical fiber slip rings.

This innovative fiber optic slip ring adopts a patented optical structure developed by itself. In addition to maintaining the basic characteristics of small size, light weight, stability and long life (200-400 million revolutions, maintenance-free), its biggest advantage is fast, thus extremely Greatly reduces manufacturing costs:

• Manually 1 second to complete the optical axis alignment;
  

• There is no need for precision fixtures in the production process;

• The production personnel have no professional experience and technical proficiency requirements;

• The finished product is assembled at one time, and the pass-through rate is as high as 100%.

After a year of market inspection, mass production has begun in early 2022 and shipped to high-end markets such as Europe, America, Japan, and Malaysia.