In the Pipeline: Photonic Signal Processing

The use of inscribing Bragg grates on individual fibers has the potential to revolutionize the logical circuits in photonic transmission and reception. Though Bragg gates have been used as filters in the past, it is the reflected component and not the transmitted component which has only recently begun to be utilized. The Spanish pioneer in photonics Ivana Gasulla has recently created a time delay cavity by inscribing Bragg grates on individual cores of a multi-core fiber (MCF).⁽¹⁾

This novel use of the Bragg grate is made possible by the brilliant use of lenses, mirrors, and masks with piezoelectric transducers to focus, aim, and collimate the transcription beam. The multi-core fiber is suspended between two CNC mounts which rotate the MCF as necessary to inscribe each individual fiber with a precise apodized gate to reflect the desired frequency. Ivana Gasulla’s fiber transcription device also has a computer-assisted translational function which allows the patterning of multiple Bragg gates along the same length of fiber. This new method will likely be used in the logical circuitry of transceivers in the future since it has the ability to resolve individual frequencies and create differential time delays among them. This new technology will provide grated fiber optic logic which has the potential to supplant some contemporary solid-state silicon circuity leading to lower prices, size, and weight.

And for those who think the limit of information processing has already been reached; think again. The technology to manufacture these novel components is already in existence and the utility is limited only by the imagination of electrical and optical engineers.