Bai Lei suddenly wanted to cry even more. Why is the gap between people so big? Teacher Chang could not be a beauty in people’s eyes.

Chen Yue also sighed, "It's really angering for people to compare with others."

This is definitely the first time Chang Qing said such kind words at a weekly regular meeting.

"Zhuoling, let's talk about the next one."

Full of encouragement.

"Dear teachers, good evening, senior sister, I am Zhuo Ling, the first time I report. If there are any omissions, please criticize and correct me. My research topic is the mitigation and compensation technology of optical fiber polarization mode dispersion. PMD is one of the main obstacles to the long-distance propagation of high-speed optical fiber communication. Due to the statistical characteristics of PMD, it is quite difficult to recover the transmission signal damage caused by PMD. My job is to summarize the current commonly used PMD mitigation technology and the current situation of photoelectric compensation technology... and to have a preliminary understanding of the compensator structure, feedback signal extraction and particle swarm optimization control algorithm in PMD optical domain compensation technology."

"It's very good. I just came into contact with the project and my professional foundation is still very weak. It's not easy. Let's continue to talk about it." Chang Qing said with a smile, and he turned into Maitreya Buddha.

The other students could only sigh that it seemed that Zhuo Ling could enter the laboratory in her sophomore year. It was not without reason. How was he doing, he would have to hear it before he knew.

Guan Debao was always upset and couldn't vent his anger. He looked at Zhuoling with a cold look and made up his mind. No matter how she said it, she must let her know that she was powerful and encountered some setbacks.

"High-rate fiber optic communication networks have become the development direction, and the dispersion chromaticity, polarization dispersion, and nonlinear effects in optical fibers have become the main factors that limit the further growth of the transmission rate of optical fiber communication systems. Regarding dispersion chromaticity, Senior Brother Bai Lei has made a detailed introduction. I will mainly talk about polarization mode dispersion. Due to its statistical characteristics, it constantly changes over time in the optical fiber link, making it quite difficult to recover the transmission signal damage caused by PMD."

Chang Qing interrupted: "I'll compensate, as the top of the FCC/Nfoec conference for the development of fiber optic communications, the articles on PMD have remained high in recent years. There were about 36 articles in 2001, more than 50 articles in 2002, which is a research hotspot. The topics in our laboratory have always been at the forefront."

As soon as this was said, not only other teachers, but also Bai Lei was very jealous. It was obvious that the research value of PMD was higher than his dispersion and color. Why? Giving a sophomore girl such a good topic. Because the subject matter is new, it is obviously easier to produce results. At that time, the opportunity to choose a prestigious foreign university will be greater.

Zhuoling continued: "In an ideal single-mode optical fiber, the interface is an ideal circular shape, but in reality, due to imperfect manufacturing technology, the cross-section is elliptical, there is stress inside, or the optical fiber is bent, and it is also affected by the ambient temperature, electromagnetic field, and vibration, causing the mode he1 and he2 to be degenerate, resulting in different propagation constants."

Chang Qing wrote a line of words on his notebook and then quietly pushed it to Liu Chen, "I'm taking care of this just right, take me to have the best tea tomorrow. I'm so greedy. I feel really uncomfortable."

Dizzy, this care is too obvious! Liu Chen was a little speechless.

Chang Qing said so clearly that other teachers naturally would not make things difficult for them. And they felt that the sophomore girl could do this in a short time and was indeed worthy of recognition. After all, it is not easy to fully understand a few documents in English. Not to mention a review analysis, it requires talent and a lot of time to focus.

Guan Debao couldn't wait any longer and interrupted directly: "We all know that due to the difference in refractive index between the fast and slow axes, the components transmission speeds on the fast and slow axes are different when light is transmitted in a birefringent optical fiber, which ultimately causes the light pulse to widen or split at the output end. This is the so-called polarization mode dispersion. The index is the pmd coefficient, which should be less than how much?"

"The currently recognized parameter setting is 0.5ps root km. Sometimes the limit situation will be set to 0.8."

"What factors do this coefficient have to do?"

"..." Zhuo Ling answered seriously.

Isn't this problem a little girl, Guan Debao was also a little surprised and continued: "In polarization-maintaining fiber, the non-uniformity of the birefringence of the fiber can be ignored, and there can be obvious fast and slow axes. The birefringence characteristics and differential group delay are described simply. They are usually expressed in vector formulas. Let's talk about the three-dimensional vector description of Stokes space."

The tone is very aggressive.

Yan Sheng said: "Teacher Guan and Zhuoling are only a sophomore after all, and they have never been exposed to Stokes Space at all. This kind of vector description requires at least the matrix theory and numerical analysis of the master's degree, which is a bit difficult."

Guan Debao said: "Teacher Yan, this is the case in theory. However, since Zhuoling has entered the laboratory, we should assume that she can learn the basic knowledge needed in scientific research. What do you think?"

Chang Qing was very unhappy. Little bastard, isn’t this a bad match for me? Just as he was about to speak, Liu Chen kicked him gently and shook his head. You took great care of him just now, and it’s not appropriate to come forward again.

"Teacher Guan is right. I really haven't understood this part thoroughly yet." Zhuo Ling replied with her head down, a little uncomfortable and able to keep calm.

"It is better not to put the content that you are not sure about. Let's talk about it clearly. Vector description is the basis. Changyuan. I think this topic is too difficult for Zhuoling." Guan Debao criticized. Several other teachers thought he was too nitpicking, and scientific research was also a progressive approach. Like Bai Lei, who has been in the laboratory for many years, has made low-level mistakes, and it is not too much to criticize. He should not be too demanding when he first came in.

I originally thought that scientific research grew up in criticism after all, but Zhuo Ling was really taught a lesson, Liu Chen was still unhappy and had a little bit of protection. Ling'er has indeed made a lot of efforts and it is also very good to do this. There is really no need to criticize for criticism or personal display. She has a bad impression of Guan Debao, and she has never seen him as strict with other students before.

"In fact, Stokes space vectors are easy to understand. Vectors must be directed and have their own set of calculation rules, especially the use of legends to represent them more intuitively." Liu Chen couldn't help but speak.

In the previous report of the five people, Liu Chen sat upright next to Changyuan without saying a word. From the beginning, everyone was puzzled, and gradually ignored him. Unexpectedly, such a young man suddenly spoke in a very arrogant tone.
Chapter completed!