Feeling the limitations of electrical methods, approaching with optical methods

An 'optical synapse-mimicking device' that artificially reproduces neurons and synapses has been developed. This has laid the foundation for the development of a neuro-mimicking optical computing technology that can store and think like the human brain.

The Electronics and Telecommunications Research Institute (ETRI) has succeeded in developing a core technology for an optical synapse-mimetic device that combines graphene, one of the two-dimensional (2D) semiconductor materials that is attracting great attention as a new material in the form of an ultra-thin film with nano-thickness, and optical communication technology.

The human brain is a form in which the storage part and the calculation part coexist. However, the computer has the storage part and the calculation part separated. If the computer has the storage and calculation part coexisting like the human brain, it can send information quickly while calculating it. This is the principle that makes optical computing that imitates the human brain nerves possible.

By changing the resistance in an electrical way, it was made possible to recognize and calculate the resistance when a signal is given. However, as the circuit became more complex, interference occurred, which limited the ability to increase integration.

So the research team took an optical approach. They changed the electrical circuit to an optical circuit. This created a photoresistive memory. They also made it possible to perform calculations using various wavelengths of light by utilizing the hysteresis phenomenon. The optical memory device created by the research team is about 20㎛ x 20㎜. In the future, we plan to develop it at the hundreds of nanometer (nm) level and highly integrate it into a chip form.

It is expected that the developed device will be embedded in a chip form for optical communication for the purpose of information transmission in the future, enabling calculations and information transmission at the same time. This will make so-called optical synaptic computing and neuro-mimetic optical computing possible.

ETRI explained that if this technology is commercialized, the time it takes for a person to see and recognize an object is usually around 0.06 seconds, but if optical computing is made possible, not only will power be reduced, but the recognition speed will also be much faster.

ETRI stated that in the future, if the original technology is applied to optical communications, an optical computing device can be created. Optical computing will soon become possible.

ETRI Biomedical IT Research Center Director Seung-Hwan Kim said, “We plan to develop a neuro-mimetic optical computing technology that mimics biological brain functions using artificial optical technology by combining the developed optical synapse-mimetic device with existing ultra-high-speed optical communication technology.”