‘Plasmonic’ material could lead to super-fast modes of optical communication


Previously, we have prattled at length about the virtues of laser and its application in a wealth of technologies. Well, this time around, scientists have concocted a new material that can actually support laser in terms of effectiveness in optical communication. We are talking about a special ‘plasmonic’ oxide material devised by a team of researchers at Purdue University. Touted to be potentially ten-times faster than regular fiber-optic technologies, the substance is made from aluminum-doped zinc oxide (AZO). According to the scientists, this composition allows the plasmonic material to regulate and alter the magnitude of light’s reflection (by over 40 percent), while at the same time requiring lesser power than comparable semiconductor components used in optical communication.

The capacity to modulate the light is certainly a crucial factor when it comes to the scope of data transmission. For example, the change in reflection can be used to directly affect the encoding of data. The alteration is also directly proportional to the change in magnitude of transmission, thus accounting for effective speeds. However in conventional terms, high speed in itself can lead to the heating up of the optical material. Interestingly, AZO eschews this problem with its ability for low energy dissipation (thus also leading to lower power consumption).

As for the other advantage of the AZO, the material was found to operate quite efficiently in the near-infrared spectrum range. This range is familiar for optical communication, and as such the material is compatible with CMOS manufacturing process that is used for producing integrated circuits. To that end, the researchers are already looking forth to create a specialized ‘optical transistor’ that works like a regular transistor, but for light instead of electricity.

The working scope of a semiconductor entails (according to Purdue) –

Exposing the material to a pulsing laser light [that] causes electrons to move from one energy level called the valence band to a higher energy level called the conduction band. As the electrons move to the conduction band they leave behind “holes” in the valance band, and eventually the electrons recombine with these holes.

Now, the so-called switching speed of transistors is directly related to how fast a semiconductor can complete this aforementioned cycle of the electrons. For sake of comparison, the cycle is completed in just 350 femtoseconds in AZO films – which makes it a whopping 5000-times faster than in crystalline silicon. When translated into practicality, this high speed scope can result in future electronics that are 10-times faster than conventional silicon-based devices.

Lastly, as for the commercial side of affairs, the scientists have observed that they can probably fine-tune the optical properties of metamaterials (due to the composition of the AZO). This might lead to setups that would allow mass-production of the plasmonic material in the near future.

Source: Purdue / Featured Image Credit: Purdue University / Nathaniel Kinsey

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