Chapter 1603 Plane Mirror Focusing

One week later.

Li Yabo held his breath and took out the two negative refractive chips that had been combined into one from the fully automatic wafer combining machine.

The fingertips were so steady that there was not a trace of trembling.

"Double negative refractive flat lens"

Thanks to the valuable experience accumulated previously, the entire process, from liquid phase controlled stripping to surface treatment and sealing, was much smoother than the first time.

Two hundred million yuan, of course it’s just a joke.

The one hundred million yuan cost of the first piece includes a large amount of research and development and procurement funds, which are one-time expenses and do not need to be taken into account in the production of the second piece.

Of course, no matter what, with the current efficiency of hand-rubbing, the cost of a single chip of eight digits is still required...

"It's done."

Chang Haonan judged.

Li Yabo nodded:

"It's done."

He could feel his heartbeat speeding up, but the sound he spoke was extremely steady, even a little deliberate.

Anyone holding such a fragile thing worth hundreds of millions would be so scared that they dare not speak.

"Try the effect?"

Someone behind me suggested.

Li Yabo grabbed a green laser pen from the side and aimed it at the lens impatiently.

A thin beam of green light shot out, passed through the lens, and hit the white board in the distance.

Because the thickness has increased a lot, the optical path is still clear even when observed with the naked eye.

But... it seems to be no different from the previous single-chip demonstration effect.

The incident light and the refracted light are on the same side of the normal.

Li Yabo frowned slightly and looked at Chang Haonan with a hint of confusion.

Chang Haonan looked at Li Yabo's slightly confused expression, and a smile of understanding appeared on the corner of his mouth.

"Of course you can't see much difference when you use a nearly monochromatic parallel laser beam." He pointed at the laser pointer, "If you use another method, it will be clear at a glance."

Li Yabo asked subconsciously: "Let's go to the optical laboratory downstairs? The equipment there is more complete..."

"I will definitely go later, but there is no need to go through so much trouble now."

Chang Haonan interrupted him and walked straight to a desk against the wall, then opened the drawer and fumbled around inside for a while.

He actually pulled out a small incandescent bulb with a metal base, two No. 5 batteries, and two wires with alligator clips at the ends...

"Here," he put the things on the table and picked up the chip, "How to do the physics experiment in junior high school, do you remember?"

Li Yabo took the "simple" equipment that was incompatible with the high-end research in front of him with a blank look, and nodded subconsciously: "Remember... series circuit."

As he spoke, he skillfully connected the batteries in series and then connected the wires to the positive and negative poles of the batteries and the metal contacts of the light bulb.

There was still a hint of student instinct in his movements.

"Very good." Chang Haonan pointed to a relatively clean white wall in the middle of the room. "Go to the floor tile next to it, face that wall, and wait for my instructions."

Then he turned to the other assistants and engineers in the room who were watching: "Xiao Liu, turn off the lights!"

"Clap!"

With a few soft sounds, the laboratory ceiling lights and operating table lights went out instantly.

The synthetic laboratory had no windows to begin with, so the entire space suddenly became pitch black.

Only the emergency channel indicator light emitted an extremely faint, almost negligible green light.

"Connect the circuit." Chang Haonan's voice rang out in the darkness, concise and powerful.

Li Yabo immediately used crocodile clips to connect the wire to the last two contacts of the battery.

The small light bulb in his hand lit up instantly. The orange-yellow light was extremely weak. Even in the dark, it could only barely illuminate a small area around the bulb, reflecting the outline of Li Yabo's palm, but it was completely unable to dispel the darkness in the room.

"Do you want another battery?"

Li Yabo frowned and looked at the dim environment.

"Don't move!" Chang Haonan shouted, "That's exactly the effect we want."

Then, he steadily raised the double negative refractive lens in his hand and placed it firmly between the small light bulb and the white wall, approximately 30 centimeters in front of the light bulb.

In an instant, it was like magic.

On the wall, which was originally almost completely black with only faint ambient light, an extremely bright circular light spot with clear boundaries suddenly appeared!

The brightness of this light spot formed an extremely strong contrast with the pitiful light of the small bulb itself, as if a powerful light source had appeared out of thin air.

Everyone in the room, even Li Yabo, subconsciously let out a low cry of surprise.

Chang Haonan did not stop, but slightly adjusted the distance of the lens.

The light spots on the wall changed accordingly, the brightness became more concentrated and the outlines became sharper.

A few seconds later, an even more shocking scene appeared - in the center of the bright circular light spot, there appeared several extremely tiny but clearly discernible, intertwined bright line outlines.

"The filament...it looks like the shadow of the filament?" someone cried out.

A completely flat lens with uniform thickness (strictly speaking, two parallel plates) without any raised or concave optical surface design can converge the divergent light from the point light source and form a clear image on the wall.

This seems to go against the basic knowledge about ordinary lenses that everyone learns since childhood.

Chang Haonan used the simplest equipment and the most basic junior high school physics experiments to demonstrate the "unbelievable" nature of negative refractive index materials in the most intuitive and shocking way - it completely subverts traditional optical properties and gives planes the ability to focus and form images!

At this moment, everyone gradually came to their senses.

The principle is actually not difficult to understand.

It's just that because it's so counterintuitive and too basic, no one thought of it at first.

Just like when you first start learning non-Euclidean geometry.

The simpler the relationship in Euclidean geometry, the more likely it is to form blind spots.

However, Chang Haonan's demonstration was not over yet.

"Don't move yet!"

He slowly moved the hand holding the lens upwards, while his wrist slightly tilted to the outside.

The light emitted by the small light bulb is essentially white light that contains a continuous spectrum.

Therefore, the change in the lens posture immediately causes dispersion.

A faint, colorful band of light, like a miniature rainbow, replaced the bright main light spot and quietly appeared on the wall.

Although it is very faint, it appears particularly clear and vivid against the almost black background.

"Dispersion..." Li Yabo murmured. This is an inherent property of optical materials. Any non-ideal material has different refractive indices for light of different wavelengths, which causes white light to decompose. This is expected.

But almost at the same time, the dispersed light bands appeared.

"Wait!" another sharp-eyed engineer in the crowd blurted out, "The colors... seem to be... in the wrong order?"

This sentence was like a stone thrown into a calm lake, instantly waking everyone up.

Everyone looked carefully.

The faint rainbow on the wall, the color closest to the side where the lens's refraction direction changes, is not the common red light.

But purple light.

Extending outwards, they are blue, cyan, green, yellow, orange...

The outermost side is red!

This is completely opposite to the color sequence that everyone is familiar with, "red on the outside, purple on the inside" in the rainbow after rain!

A satisfied smile finally appeared on Chang Haonan's face.

He lowered his arm and replaced the lens in its protective case.

The magical spots of light and the reflected rainbow on the wall disappeared instantly, as if everything that had just happened was just an illusion.

But the shock and excitement that remained on everyone's face proved that it was not an illusion.

"As you can see," Chang Haonan's voice broke the brief silence, "while the material exhibits a negative refractive index, it also produces an equally 'negative' dispersion characteristic."

“Dispersion compensation!”

In the darkness, more than one person shouted these four words.

Almost in unison.

Of course, Li Yabo is also included.

Chang Haonan just gestured towards the door and said, "Xiao Liu, turn on the light."

"pat-"

Light returns to the laboratory.

Li Yabo was almost overjoyed. Even before his eyes had fully adapted to the bright light, he said, "Teacher, I will start designing a verification achromatic system right away!"

The rest of the people were also rubbing their hands, looking eager to try.

There is no other reason, it is just too attractive——

In order to achieve achromatic aberration in a conventional lens system, two or more materials with different dispersion properties must be combined into a composite lens.

For example, a low-dispersion BK7 crown glass and a high-dispersion F2 flint glass are combined together to form a "double-cemented lens", and their dispersion directions are the same but the degree of difference is used to compensate for each other.

However, no matter how many positive numbers are superimposed, the result will only be a positive number. Therefore, the best that can be achieved is to eliminate the dispersion difference, but it is impossible to completely eliminate the dispersion.

Moreover, this idea is only applicable to narrowband spectra and is powerless against dispersion differences in wider bands.

In addition, the combination of multiple lenses sounds simple, but the lens group always has other functions. Eliminating dispersion difference is a means rather than an end. Therefore, the design difficulty and manufacturing cost of engineering implementation are very high. It often takes a huge price to eliminate the dispersion difference of binary wavelengths.

The emergence of negative refractive index materials has brought about a disruptive solution.

Its negative dispersion characteristic is equivalent to introducing a new "degree of freedom" with opposite sign.

In theory, it is even possible to achieve truly perfect achromatism across a wide wavelength band.

Even if it cannot be absolutely perfect, it can make the traditional achromatic design easier than ever before.

This is undoubtedly a revolutionary breakthrough for cutting-edge fields that rely on ultra-wideband imaging or require extreme dispersion control.

However, Chang Haonan smiled and waved his hand.

"Yabo, this direction is very important and has broad prospects, but the specific design, testing and engineering verification work can be handed over to Xiao Liu to promote."

The excitement on Li Yabo's face froze instantly:

"Teacher, then... me?"

As Chang Haonan's founding disciple, he doesn't have to worry about others taking advantage of his achievements.

Just a little surprised.

Chang Haonan tapped the protective box on the table:

"I have a more important conjecture that I need you to verify..."