Chapter 1624 Super Resolution Lithography

Luan Wenjie's gaze was fixed on the last clear "Group 11, Element 4" logo on the screen, as if time had stopped.

173nm——

After the brief excitement ended, he couldn't help but start thinking about the deeper meaning behind this number.

The diffraction limit is the theoretical upper limit of resolution in optical systems formed by the diffraction effect of electromagnetic waves, and is an extension of the wave-particle duality of light.

To put it in a broader sense, it can even be considered one of the cornerstones of modern physics and even modern science.

And the scene that just happened before his eyes seemed to shatter this cornerstone easily.

Faced with this situation, anyone who knows the history of science will immediately think of more than a century ago.

That shattered the progress of classical physics.

"Academician Chang..."

As soon as he opened his mouth, Luan Wenjie was almost scared by his own dry voice.

After rolling the larynx a few times, I finally regained my original feeling.

"Tell me something..." He leaned forward and asked in a low voice, "Are there two more 'dark clouds' floating over the sky of modern physics?"

Obviously, Luan Wenjie tried to make his question easier.

But obviously failed.

Instead, Chang Haonan smiled and responded half-jokingly:

"Director Luan, I don't know much about meteorology, let alone weather forecasting."

However, the other party's expression became more serious.

"I am serious, Academician Chang, you should understand what I mean."

He took a step forward and stared at Chang Haonan with burning eyes:

"This result... This is no longer just testing the edge of the cloud. If there is no new discovery that can shake the existing laws of physics, how could the resolution of a lens... so easily exceed the diffraction limit?"

Of course Chang Haonan could understand the other party's shock.

In fact, when he first deduced this possibility theoretically, he felt that there must be something wrong between him and Einstein.

But later it turned out not to be the case.

Both of them are right.

"Director Luan, you are only half right." He waved his hand gently: "In fact, in this system, the one that is truly responsible for imaging is not the 'lens' in the traditional sense."

After that, he ignored Luan Wenjie's still confused look and just signaled to Li Yabo beside him: "Yabo, remove the sunshade."

Li Yabo immediately stepped forward and carefully removed the black cylindrical lens hood.

The scene on the platform was instantly visible.

"From the perspective of the optical model," Chang Haonan pointed at the exposed core area, "it is two lenses that together form this imaging system that breaks the limit."

Luan Wenjie immediately moved closer, almost putting his face close to the optical platform, and looked at it carefully:

A seemingly ordinary, smooth-surfaced flat lens.

And, placed right behind it is a... translucent flat plate?

"Is this it?" Luan Wenjie pointed at the tablet and looked at the imaging screen in the distance.

"No, no, no..." Chang Haonan shook his head. "The one at the back is the imaging plate. The other lens I mentioned actually refers to the gas in this system."

Luan Wenjie seemed to understand a little:

"So the light just now first passes through the lens to form an image on this flat plate, and then the image on the flat plate... is received and displayed on the imaging screen?"

"That's right." Chang Haonan nodded in approval of Luan Wenjie's keen observation. "Of course, the imaging screen can also block the light path to prevent the high-intensity laser beam from emitting out of the test range and affecting other equipment or people."

Luan Wenjie subconsciously stretched out his hand and wanted to gesture next to the lens and the tablet.

But then he remembered that he probably couldn't touch this thing casually, so he shrank back and asked:

"Then why do we put the imaging plate right next to the lens?"

"Actually there is a gap, about 1.5 microns." Chang Haonan gestured to indicate an extremely small distance, "It's just difficult to distinguish with the naked eye."

He put on special anti-static gloves and carefully removed the core plate located between the lens and the plate - that was the real imaging element.

Then, start answering the other person's initial question.

"The fundamental reason why the diffraction limit exists is that traditional lenses cannot focus light to an area smaller than half a wavelength."

Chang Haonan held the special tablet in his hand and showed it to Luan Wenjie:

"But our idea is to make light 'negatively refract' at a set of material interfaces with equal absolute values of refractive index but opposite signs."

He pointed to the lens and the tablet in his hand:

"To be specific, we can focus the light emitted from the target object on our flat plate made of negative refractive index material. In theory, we can bypass the constraints of the diffraction limit and achieve perfect imaging."

As he spoke, his eyes swept across the unclear 173nm resolution target pattern on the screen.

So he added:

"Of course, in actual operation, the imaginary loss of the material and the mismatch of the interface impedance will introduce losses, affecting the transmission distance and final resolution of the evanescent wave, so it is still impossible to achieve theoretically perfect imaging... But it is still very easy to compress the effective imaging resolution to about half of the diffraction limit, as we have just seen."

"If we use a light source with a narrower spectrum width and a purer spectrum, combined with further optimization of the material process, we can probably push it further to a quarter."

Luan Wenjie stood there, feeling as if his brain had experienced an information storm.

He heard every word of Chang Haonan's explanation, but those terms - "negative refraction", "evanescent wave", "impedance matching", "imaginary loss" - combined together formed a completely new physical picture that he found difficult to fully understand and digest in a short period of time.

That feeling is not a simple "not understanding", but the shock of having one's cognitive framework forcibly stretched or even partially torn apart.

This shocked him more than simply seeing the result of breaking through the limit.

For a full half minute, he just looked at the tablet in Chang Haonan's hand, then looked at the clear image on the screen. His lips moved, but no sound came out.

As the director of the Industrial and Construction Committee, he is well aware of the strategic value of this disruptive technology, but precisely because of this, the heaviness that comes from the unknown is even stronger.

However, even if there were no outsiders around, it would not be appropriate to maintain such a stunned look for too long.

"Cough cough..."

Luan Wenjie cleared his throat, preparing to temporarily skip the optical theory part and bring the topic back to a more practical level:

"Academician Chang, I understand... Well, at least I understand that this is of great significance." He pointed at the screen, "This test result... Can I have a copy to take back? When reporting to your superiors, this intuitive evidence will be more convincing than any words."

Chang Haonan waved his hand:

"Director Luan, this test was successful as a proof of principle, but it is still too abstract to be used as material for presentation to non-professionals."

It is true that most of China's decision-makers come from science and engineering backgrounds, but after decades away from front-line technical work, they may not be able to remember much specific knowledge.

He put the lens in his hand back to its original position and continued:

"I plan to use our lens based on the principle of negative refraction and a traditional PMMA (organic glass) lens to simultaneously expose and image a specially designed complex microstructure pattern with 200nm line width features, and then use an atomic force microscope (AFM) to scan the surface morphology of the imaging results of the two."

"When the time comes, the three-dimensional morphology images scanned by AFM will be placed side by side - one side is an image with clear details and sharp edges, and the other side is a fuzzy 'mosaic' with no discernible structure... The visual impact will be even stronger."

This plan was obviously well thought out, and even people who don't understand physics can see the difference at a glance.

"Good! This is good!" Luan Wenjie imagined the two contrasting images, and his tense nerves finally relaxed a little. "Very intuitive! Then I'll wait for your AFM comparison pictures!"