7: Chapter 7 The Light Chasing Project Team

Life in Room 103 of the old laboratory building was calm and fulfilling.

Lin Shen quickly adapted to the environment and rhythm here. Engineer Li did not speak much, but he possessed solid technical skills and rich experience, knowing the temperaments of these old pieces of equipment like the back of his hand. Under his guidance, Lin Shen mastered the safety operation protocols and simple maintenance techniques for various basic equipment at an astonishing speed. From cleaning glassware to calibrating microscope optical paths, and from replacing the sealing rings of the vacuum coating machine to oiling the lathe, he did everything meticulously.

Initially, Engineer Li held a somewhat observant and reserved attitude toward this young Assistant Researcher who had been "parachuted" in and was rumored to have once been a "genius." He had seen too many so-called top students who had high standards but low abilities and disdained such "menial work." However, Lin Shen's steadiness, focus, and learning ability quickly won his approval. What surprised Engineer Li most was that Lin Shen had an exceptionally thorough understanding of equipment principles; he could often offer maintenance suggestions that touched upon the essence of the problems and could even decipher complex hand-drawn circuit diagrams and mechanical schematics.

"Kid, you've got a good foundation." One afternoon, after Lin Shen determined that a bearing in the polishing machine needed pre-tightening just by listening to the sound, Engineer Li offered a rare compliment, although his face remained expressionless.

"It's all thanks to your teaching, Engineer Li, and your detailed notes." Lin Shen smiled and took off his oil-stained gloves. His body was recovering faster and faster through regular labor and continuous rehabilitation; his arms were regaining muscle definition, and his complexion was becoming ruddy.

During the day, he dutifully completed the auxiliary work assigned by Engineer Li, received students or personnel from other project teams who occasionally came to use the equipment, recorded data, and organized the laboratory. These tasks took up some of his time, but they also allowed him to become more deeply familiar with the performance limits and potential issues of each piece of equipment.

He devoted most of his energy to two things.

First, he used the laboratory computer and the Assistant Researcher account permissions provided by the institute to search for information with all his might. The databases he could access now were much richer than that "basic visitor" account from before; they contained not only more comprehensive journal papers but also a large number of doctoral dissertations in related domestic fields, internal technical reports, project completion abstracts (non-classified parts), and even some unpublished discussion records from academic conferences.

These materials, like nutrients, continuously nourished the deduction of the technology tree in his mind. The progress of the deduction regarding the synthesis path for "ultra-low-loss Photonic Crystal" was still slow, but every step was becoming more solid and concrete. He began to be able to filter out a few of the most feasible technical routes and had a clearer prediction of the key steps and potential obstacles involved.

Second, it was that old-fashioned Scanning Electron Microscope (SEM) he had been thinking about constantly.

This ancient model of equipment was the most "advanced" asset in the laboratory, but it was also the least favored. It was said that many years ago it had been a primary piece of equipment, but later, as the institute purchased newer and more advanced SEMs, it was moved here for teaching and simple morphology observation. However, due to complex maintenance, hard-to-find parts, and an obsolete image processing system, it had been idle for nearly two years, gathering dust under a dust cover.

Yet, Lin Shen developed a great interest in it. While organizing the equipment files one time, he found the complete technical manual and maintenance logs for this SEM. After careful study, he discovered that the core part of the electronic optical system of this equipment was actually well-maintained; the main problems were a minor leak in the vacuum system (causing slow and unstable vacuum pumping), aging of some circuit boards leading to unstable control signals, and the fact that the accompanying computer and image acquisition card were completely obsolete and incompatible with current systems.

He cautiously sought Engineer Li's opinion.

"That old antique?" Engineer Li was wiping a balance and didn't even look up. "You want to touch it? The parts have long been out of production, and the institute won't apply for maintenance funds for it. Besides, even if you fix it, the resolution won't keep up with current demands, and it's noisy."

"Engineer Li, I just want to try." Lin Shen said sincerely. "I've read the manuals and logs, and I don't think there's absolutely no hope. Even if I can only restore basic functions in the end, it would be good for students to observe the morphology of samples at the micron scale, or for me to practice and familiarize myself with the principles and operation of the SEM. I can slowly figure out some basic cleaning, seal ring replacement, and circuit checks myself; no extra funding is needed."

Engineer Li stopped what he was doing and glanced at Lin Shen, as if trying to see something in his eyes. Finally, he sighed and pointed to a dust-covered toolbox in the corner: "Fine, it's just sitting idle anyway. There are some old tools and potentially useful spare parts there; handle it yourself. Remember, safety first! Don't mess with the high-voltage parts and the electron gun! The vacuum pump oil needs changing; under the bottom shelf in the back of the storage room, there seem to be a few bottles of compatible old-model oil. Go take a look. Call me when you need a hand."

"Thank you, Engineer Li!" Lin Shen's spirits lifted.

In the following days, outside of completing his daily work, all of Lin Shen's spare time was devoted to this old SEM. He treated it like a precious work of art, first carefully cleaning off the thick dust, then checking and testing it component by component while referring to the manual.

Using other equipment in the laboratory, he made a simple leak detection tool (an alternative method to a helium mass spectrometer leak detector, combined with soapy water) to check for leaks in the vacuum system bit by bit, replaced all aging rubber sealing rings and gaskets, and re-tightened all flange connections.

The circuit part was even more troublesome. Relying on some circuit diagram annotations in Engineer Li's old notebook and his own solid foundation in electronics, he used a multimeter and an oscilloscope (another barely usable old piece of equipment) to test the voltage and signals of key control boards one by one. He found several traces of bulging capacitors and burnt resistors and replaced them by scavenging components with similar parameters from discarded old instrument circuit boards. This process was full of uncertainty; several times during power-on tests, small sparks or a burnt smell appeared, making him fearful, but fortunately, everything turned out safe in the end.

The trickiest part was the computer system. The original dedicated industrial computer was completely scrapped. Lin Shen tried to connect his own old laptop to the SEM's main controller via the ancient GPIB interface (a standard instrument bus from the last century) and spent a lot of time writing and debugging an extremely rudimentary control and image acquisition program modified from open-source code. This process almost exhausted all his programming knowledge reserves, involving countless crashes, debugging, and crashes again.

Engineer Li would occasionally come over with his hands behind his back to take a look, not saying much, only giving a hoarse reminder when Lin Shen encountered obvious danger or went down an obviously wrong path: "That fuse is custom-made, don't just replace it." "The GPIB card address is conflicting, change the jumper."

Two weeks later, on a weekend afternoon, Lin Shen was the only one in the laboratory. Outside the window, a drizzling spring rain was falling.

He completed the final circuit check, took a deep breath, and pressed the main power switch. The familiar humming sound started, and the indicator lights lit up one by one. The vacuum pump began to work, and the noise was lower than he had expected. He stared at the rudimentary control interface he had written, watching the vacuum degree value slowly but steadily decrease.

Ten minutes later, the vacuum reached the working range.

He held his breath, placed a silicon wafer sample that he had prepared in advance and coated with a gold film onto the sample stage, and inserted it into the sample chamber. He operated the mechanical pump and valves, and locked it.

Then, he cautiously and gradually increased the filament current of the electron gun and adjusted the accelerating voltage. On the control interface, the beam current indication began to appear.

He focused the electron beam on a scratch on the sample surface and began to scan slowly.

On the screen, amidst the original noise and snow, blurry, jumping lines and outlines began to appear. The image was very unstable, and the noise was significant, but... it had indeed appeared!

Lin Shen's heart pounded wildly, and his hands trembled slightly. He continuously fine-tuned the focus, astigmatism, contrast, and brightness. The image on the screen gradually became clearer—it was the granular structure of the gold film on the silicon wafer surface, as well as the edge of a clear scratch!

Although the resolution was far inferior to a modern SEM and the image was full of noise, this old piece of equipment that had been silent for years had truly "come back to life" in his hands!

An indescribable sense of accomplishment surged in his heart. This was not only an affirmation of his technical ability, but more importantly, he now possessed a window to peer into the microscopic world! Even if this window was somewhat blurry, it was enough to allow him to observe the surface morphology, particle size, and defect distribution of the materials he might prepare in the future... For materials research, this was the foundation of foundations, the eye of eyes!

He excitedly observed the morphology of different areas, tried different shooting parameters, and saved the images. Although the quality was poor, each one was like a treasure to him.

Just as he was immersed in this "joy of creation," the laboratory door was knocked.

The person who came was a staff member from the institute's Scientific Research Department, notifying him to go to the small conference room; Deputy Director Professor Zhang Mingyuan had something to discuss with him.

Lin Shen was stunned for a moment, suppressed the excitement in his heart, closed the SEM, tidied his clothes, and followed the staff member out of Room 103.

In the small conference room, besides Professor Zhang Mingyuan, there were two strangers sitting there. One was a woman in her forties with a capable temperament and rimless glasses, and the other was a man in his early thirties with a tall, upright stature and sharp eyes. Both were dressed in casual clothes, but their posture was upright, and their temperament was clearly different from ordinary researchers or administrative staff.

"Lin Shen has arrived, sit down." Professor Zhang Mingyuan greeted, a gentle but slightly complex smile on his face. "These two comrades are... sent by the higher-level department to conduct some technical research and talent assessment work. They have some questions they would like to ask you."

Lin Shen felt a stir in his heart, but kept a calm expression as he sat in the empty seat: "Hello, Professor Zhang. Hello, leaders."

The capable-looking woman spoke first, her voice clear and pleasant, yet carrying a professional rigor: "Comrade Lin Shen, hello. We are researchers from the 'National Frontier Technology Assessment and Planning Office'. My surname is Zhou, and this is Comrade Wang. We have noted that you have recently resumed work and have been carrying out equipment maintenance and technical exploration in the old laboratory building, especially in the repair of the scanning electron microscope, where you have demonstrated excellent technical foundation and hands-on ability."

She paused, looking at Lin Shen with a calm gaze: "We are currently cooperating with some major national strategic requirements to conduct a broad screening of fundamental technical talent and potential directions. As a young researcher who has just returned to a scientific research post, we would like to hear your thoughts and plans regarding your future research direction. Especially against the backdrop of the country facing certain key technological bottlenecks."

The question was very broad, yet a sense of direction seemed to faintly exist.

Lin Shen's heart tightened slightly. Had it come? Was this the aftermath caused by that email? Or was it just a normal, extensive talent survey?

He quickly organized his thoughts and decided to start his answer with the direction he was most familiar with and also the "safest."

"Researcher Zhou, Comrade Wang, Professor Zhang," Lin Shen said in a steady tone. "My main energy is currently focused on physical recovery and re-familiarizing myself with the scientific research environment. The work in the old laboratory building has given me the opportunity to revisit many basic experimental skills and equipment principles, which is a very good review and accumulation for me."

"Regarding future research directions," he paused slightly. "My personal interests and foundation are mainly in new energy materials and related condensed matter physics fields. Of course, due to the three-year blank period, I need to make up for a lot of lessons and understand the latest developments. However, in the process of daily equipment maintenance and reading materials, I have also come into contact with some interesting problems in other fields. For example..."

He carefully chose his words, selecting a very basic branch point derived from the [Photonic Chip Basic Architecture] node on the technology tree, one that seemed to relate to his current identity as an "equipment maintainer."

"For example, in the process of trying to repair that old SEM, I deeply studied its electron optical system and vacuum system. This reminded me that one of the core bottlenecks for many modern high-end precision manufacturing and testing equipment, such as extreme ultraviolet lithography (EUV) and atomic layer deposition (ALD), lies in the stable maintenance of ultra-high vacuum and the manipulation and detection of precision particle beams (photon beams, electron beams, ion beams). And these technologies share some commonalities with next-generation information devices, such as potential Photonic Chip Basic Architecture or more advanced integrated circuits, at the level of basic physics and engineering technology."

He did not directly mention Photonic Chip Basic Architecture, but instead cut in from the more basic and general perspective of "equipment technology bottlenecks."

"I believe that if breakthroughs can be made in these fundamental ultra-high vacuum technologies, precision beam control technologies, and related special material and interface research, it might provide some underlying support for breaking through higher-level, systematic technical blockades. Of course, these are just my own very shallow and immature thoughts, and I still need to study further."

This answer demonstrated his certain technical vision and depth of thinking, while cleverly avoiding direct involvement in sensitive fields (such as specific Photonic Chip Basic Architecture design), making it sound more like a young researcher with ideas focusing on basic common technologies.

Researcher Zhou and Comrade Wang exchanged a glance. Comrade Wang spoke, his voice deeper: "Fundamental support technologies are indeed very important. Comrade Lin Shen, which specific directions are you referring to regarding the precision beam control and special material interfaces you mentioned? Do you have more specific ideas or points of focus?"

The question went a step deeper.

Lin Shen felt vigilant, but his mind raced. He decided to throw out some "solid content," but kept it within the scope of "reasonable speculation" and "literature inspiration."

"For example," he said, "I have recently read some review literature on 'Photonic Crystal' and 'metasurfaces'. These fields aim to manipulate light fields through artificially designed micro-nano structures. Their realization is extremely dependent on the precise processing of sub-wavelength scale structures and the optical properties of specific materials. This relates to what I just mentioned, how to achieve stable, high-precision particle beams (such as focused ion beam FIB) or energy beam processing, and how to understand and control the behavior of light at the interface between these artificial materials and natural materials. There are both physical problems and engineering challenges involved."

He mentioned cutting-edge concepts common in public literature, without involving any specific technical details or the results of his own deductions.

Researcher Zhou nodded and recorded something in her notebook. Then, she changed the subject and asked seemingly casually: "Comrade Lin Shen, you were in a coma for three years and have become quite disconnected from the frontiers of academia. In the process of relearning, have you discovered any technical directions that you find particularly impactful, or that you think might be key breakthroughs in the future?"

This question faintly pointed towards "information acquisition" and "judgment."

Lin Shen answered cautiously: "The most impactful thing is perhaps the speed of cross-integration between artificial intelligence and various disciplines. In addition, the progress of quantum computing from theory to prototype is also impressive. As for key breakthroughs..." He pulled the topic back to the relatively "safe" basic field again, "I personally feel that new materials, especially those with exotic quantum effects or extreme environmental adaptability, as well as the tools and methods capable of precisely manufacturing and measuring these materials, are always the underlying engine driving scientific and technological progress."

The Q&A lasted for about twenty minutes. The two researchers' questions covered a wide range, sometimes delving into technical details, sometimes examining thinking logic and vision, and sometimes returning to personal experiences and recovery status. Professor Zhang Mingyuan mostly just listened, occasionally adding a few words about Lin Shen's past performance.

Finally, Researcher Zhou closed her notebook and smiled: "Thank you for your time and your candid sharing, Comrade Lin Shen. We have understood your situation. We hope you will continue to work hard, take care of your health, and strive to achieve better results soon. The country needs talent in all aspects."

"Thank you, leaders, for your concern. I will continue to work hard." Lin Shen stood up.

The two researchers shook hands with Professor Zhang Mingyuan and left, without any unnecessary pleasantries.

After they left, Professor Zhang Mingyuan patted Lin Shen on the shoulder and said meaningfully: "Little Lin, work hard. Gold will always shine. However, for some things, it is better to let nature take its course."

Lin Shen understood the implication behind Professor Zhang's words and nodded: "I understand, Professor Zhang. Thank you."

Returning to Room 103 of the old laboratory building, Engineer Li was replacing the heating wire for an oven and asked without looking up: "Finished talking?"

"Yes." Lin Shen replied.

"How did it go?"

"Just some routine research, asked about some thoughts on research directions."

Engineer Li said "Oh," and did not ask further, just saying faintly: "The image on that SEM seemed a bit more stable this afternoon than this morning?"

Lin Shen felt a warmth in his heart, knowing that Engineer Li had actually been paying attention to his progress. "Yeah, I adjusted the power supply for the scanning coil, it's a bit better. But the noise is still loud."

"Take your time." After saying this, Engineer Li returned to his work.

Lin Shen walked to the SEM that had just been "resurrected" and gently touched the cold metal casing. His heart, however, was in turmoil.

Those two "researchers" were definitely not ordinary people. Their questions, their temperament, and that final sentence, "The country needs talent in all aspects"... all implied some deeper intention.

Was it that email? Had they already investigated him? Or was this really just a broad talent screening, and he just happened to enter a wider field of vision because of the SEM repair?

Regardless, one signal was clear: he, Lin Shen, this marginal Assistant Researcher who had just woken up from a vegetative state and been "exiled" to the old laboratory building, had already begun to attract attention at certain levels.

Is it a blessing or a curse? Is it an opportunity or a risk?

He did not know.

But he knew that the technology tree in his mind, the blueprint for that [Photonic Chip Basic Architecture], was becoming increasingly clear. The deduction of the second prerequisite, stimulated by the new materials obtained and the "sense of practice" brought by repairing the SEM, had just struggled forward by another 1%, reaching 53%.

The road still had to be walked step by step. Experiments still had to be done bit by bit.

He looked out the window; the rain had stopped, and the sky was as clear as if it had been washed. The leaves of the camphor trees were shining green.

Whether it was the anonymous email from "deep shadow" or the sudden visit from the "researchers," they were just ripples occasionally stirred up on this long road.

And what he had to do was to continue to settle his heart, in this simple laboratory, using this old SEM, along with countless days and nights of thinking and deduction, to truly light up the first leaf belonging to light on that tree.

The road to Chasing Light, perhaps, had welcomed the first glance of scrutiny earlier than he had imagined.

And he, was ready.