Laser Pulses for Ultrafast Signal Processing Could Make Computers a Million Times Faster
A new type of logic gates was created by combining two ultrafast lasers. This allows the creation of more powerful computers in the future.
Computers use transistors to process information. Transistors are tiny pieces of metal or semiconductor material that act as switches. A transistor controls an electrical current by allowing or blocking it. When a transistor allows electricity to flow, it creates a voltage difference across two terminals. This voltage difference represents a binary digit, 0 or 1. By using millions of transistors, a computer can perform billions of calculations every second. But there are physical limitations to how small transistors can get. At some point, it won’t be possible to shrink them any further.
Light is faster
Physicists are trying to use light waves to control electronic devices. Light waves take about one femtosecond to complete an oscillation. This means that if you want to send information using light, you need to be able to transmit data within one femtosecond. A femtosecond is one-billionth of a second. So, if you want to send data using light, you need a computer that operates at least one-billion times faster than the speed of light.
From light waves to current pulses
Electronics are designed to transfer and convert signals into electrical pulses. Researchers from the chair of Laser Physics have been experimenting with how light waves can be transformed into electrical pulses. Their experiments show that when illuminated by an ultra-short pulse of light, electrons in graphene move towards gold electrodes. This movement generates electric currents that can be used to transmit information.
Real and virtual charges
Graphene is a thin layer of carbon atoms arranged in a hexagonal lattice. Electrons move freely through this material. The researchers used lasers to create a disturbance in the graphene. As the electrons moved, they created a type of charge called a virtual charge. Virtual charges are similar to real charges but do not exist until the electron moves.
Virtual charges are like scooping water from the edge of a pool without waiting for waves to form. In this scenario, a laser pulse would be directed towards the edge of the graphene next to the gold electrodes, and the electrons would move very fast. This means that there would be a lot of energy stored in the electron cloud.
Logic with lasers
A laser physicist has demonstrated a new way to control electrons using lasers. He uses two lasers to excite electrons in a semiconductor material. When he measures the flow of electrons, he sees if there is an aggregation or erasure of the electrons. This means that he can use the flow of electrons to perform binary operations.
This is an excellent example of what happens when you do some basic research. You discover something interesting about your subject, and then you use this information to create a new device. This device could be used to make computers faster or more powerful.
Lightwave electronics is a feasible technology.
