Nanophotonics: Lighting the Way For The Future
It’s 1940. The United States just got into World War II, and they have to fight off German forces to prevent Hitler from inciting mass destruction. They’ve intercepted German secret messages, but they have no clue what to do with it. It’s filled with high-level German encryption methods, so there’s no way that a human can decrypt it.
Any HUMAN can. Enter all-electronic computers that could perform calculations faster than the blink of a human eye! These computers were lightning fast. For its time…
Looking back at these computers, they kind of suck. At this time period, these computers could process data extremely fast, but they were extremely expensive and would take entire rooms.
Moore’s Law
As time went on, these computers got better and better. Just to understand the scope of improvement in just the last sixty years, let’s take the size of a transistor. It drastically decreased from 0.0004 meters in 1947 to just 0.0000000065 meters! That’s much smaller than a human hair!
Look at the chart above, showing the transistors per square millimeter over time. Scientists started to recognize this inherent phenomenon that was occurring, that the transistor size was decreasing at a pretty linear rate. Called Moore’s Law, this shows that the size of transistors has been decreasing pretty much every year while the amount of transistors are increasing.
We’ve now gotten to the point where computers that once spanned entire rooms can now simply be processed on the space of a single dime. But, something is happening that is causing Moore’s Law to grind to a stop. Computer clock speeds aren’t getting any faster.
This makes sense. The transistor sizes are approaching the size of a nanometer, so it’s becoming much harder to fit more transistors into a single chip because of all the different phenomena that occur in the quantum realm. Maybe we can’t decrease the size of the transistor, but what if we optimize the connection speed between them? Enter nanophotonics.
What are Nanophotonics?
Using integrated circuit technology, scientists have created a method of connecting transistors so that they can speak to one another. Note that transistors are extremely simple, usually just having three terminals, because of how small they are. Transistors act as electronic switches that can either be in the “on” or “off” state and are combined with logic gates to make complex calculations.
Our current method of connecting these transistors using copper wires may work for smaller speeds, but as the processing speeds start to increase, the signal tends to degrade as the copper wire can not handle the heat.
This is the main reason why computer clock speeds are unable to increase; even if you fit more transistors onto a single chip, if you can’t counteract the heat that is generated by the copper wires, then the processing speeds will never increase. This is why the field of nanophotonics is so promising inside the electronics industry currently because of its far-reaching applications.
Think about fiber optic cables. They move extremely fast, providing incredible speeds to different areas around the world. What the field of nanophotonics aims to do is bring those fast speeds to a computer chip using photons. Before, electrons were used to transmit the information, but photons provide for a quicker and more accessible transfer of data.
By replacing these copper wires with these optical cables, we are essentially bringing the speeds and bandwidth of fiber optics to nanoscale chips.
Challenges of Nanophotonics
This sounds amazing, but just like with every other emerging technology, there are some challenges that need to be addressed before continuing.
One main issue lies with silicon. Silicon is used essentially everywhere in electronics, so it would be economically impractical to change the computational infrastructure just to make computer speeds faster. However, silicon is terrible at mixing optical signals. These photonic devices that convert optical signals need to be scaled downwards so that they fit into the nanoscale size of many of these transistors; otherwise, it can’t be applicable.
One solution that is currently being tested right now is to use nanometer scale antennas to reduce the optical signal wavelengths and transmit the information more efficiently; however, this is still in the beta phase and needs more testing before being integrated in the real world.
Another challenge lies in its efficiency because of the limited interaction that a beam of light can have with such a small structure; however, these limitations are currently being overcome through resonant structures to make the effective size bigger than the structure itself.
Scientists are addressing these issues to try so that they can integrate nanophotonics with electronics, and they are making considerable progress. I think the thing that makes scientists the most excited about this field of study is that this can increase processing speeds at a scale never seen before, completely changing Moore’s Law and the processing power of transistors.
Other Applications
Along with silicon nanophotonics, this technology can be seen a wide variety of applications, ranging from detecting COVID-19 illnesses to neuromorphic (mimicking neurobiological architectures) and quantum computing to artificial intelligence. This technology is revolutionary, and it has massive implications for the future. Comment your favorite application to nanophotonics in the section below!
At least for me, I’m extremely excited about the integration of nanophotonics in the field of quantum computing. MIT research students have made a photonic device that allows for photon-photon interactions at room temperature. Let me say that again. QC can be done at room temperature!
This is mind-boggling and can lead to so many different technological advancements. I think the main barrier to quantum computing is that it needs to be kept at close to absolute zero for the superconductive properties to kick in, but this can surpass that barrier and lead to large strides in fields like cryptography and extensive mathematical computations.
Nanophotonics is only one section in the vast field of nanotechnology. There’s so much to explore in the field, from preserving food to safely delivering important drugs. This is such an exciting field, and I’m definitely going to research more! Stay tuned for more nanotech articles in the future!
TL;DR
- For the past 60 years, transistor sizes have been decreasing while processing power has been increasing at a linear rate.
- However, we have hit a stopping point since the copper wires connecting the transistors burn out due to the processing power they need to handle.
- Nanophotonics provide an accessible solution to this problem by using optical light signals similar to fiber optic cables to allow for faster processing power.
- It is difficult to convert these optical signals using existing materials like silicon, but great strides are being made to counteract this issue.
- There are many applications to field of nanophotonics, ranging from quantum computing to artificial intelligence.
Additional Resources
- Video: Silicon Nanophotonics: Turn Off The Dark (if you want to learn about advances to counteract the challenges discussed in the article)
- Video: Engineering Light: Nanophotonics at Columbia Engineering (if you want a brief overview to the field of nanophotonics)
- Video: Intro to Nanophotonics (if you want an extremely in depth explanation into the field of nanophotonics)
- Article: Nanophotonic Processor Uses Optics to Speed Deep Learning Computations (if you want nanophotonic applications in AI)
- Article: An Introduction to Nanophotonics (if you want additional applications in the field of nanophotonics)
Hi! I am a 16 year old currently interested in the fields of machine learning and biotechnology. If you are interested in seeing more of my content and what I publish, consider subscribing to my newsletter! Check out my January newsletter here! Also, check out my LinkedIn and Github pages. If you’re interested about personal mindsets or just stuff in general, sign up for a chat using my Calendly.
