A Non-volatile Quasi-Continuous All-Optical Fiber Programmable Platform Based on GST-Coated Microspheres

Abstract

It is recognized to be challenging to develop a continuous programmable platform for all-optical modulation characterized by macro-scale, long-distance transmission, and effective regulation. This study combines low-loss optical fiber and Ge2Sb2Te5 (GST)-coated microspheres for the first time to demonstrate a large-scale, non-volatile, and quasi-continuous all-optical programming platform. With the help of external modulation of a 793 nm continuous-wave (CW) laser and 532 nm nanosecond pulsed laser, the all-optical modulation scheme here allows the repeatable operations between switching states and provides convenient and reliable access to any potential from 0 to 8 levels. The multi-level modulation is realized by a 793 nm CW laser with different output powers from 6.1 to 12.1 mW, and the reset step is implemented by two 532 nm nanosecond pulses with an average power of 45 mW. As a result, a non-volatile optical modulation with a high extinction ratio, as large as 15 dB, is demonstrated. Moreover, a demonstration of alphabetic compilation in principle is performed to prove the practical potential of the proposed all-optical modulation system in the construction of the storage memory and the programmable platform. Hopefully, this study can lay some experimental basis and operating experience for all-optical fiber non-volatile optical networks from micro to macro.

All-Fiber Synapse Utilizing Phase Change Materials for Information Recognition and Processing

“…GST, − a type of phase change material, has 10 11 switching capabilities, fast-switching times, nonvolatile reversible phase transition between amorphous (a-GST) and crystalline (c-GST) states, , and multilevel modulation capability, making GST an excellent candidate for synaptic function. Martins et al hybridized GST with side-polished single-mode optical fibers (SMF-28) to report a reconfigurable optical attenuator .…”

“…Mimicking synapse directly on fiber offers high transmission efficiency, flexible interface control, and low cost, providing operational experience for data recognition and processing in emerging fiberized remote telecommunication networks. 31−33 ■ PRINCIPLE GST, 34−36 a type of phase change material, has 10 11 switching capabilities, 37 fast-switching times, nonvolatile reversible phase transition between amorphous (a-GST) and crystalline (c-GST) states, 38,39 and multilevel modulation capability, making GST an excellent candidate for synaptic function. Martins et al hybridized GST with side-polished single-mode optical fibers (SMF-28) to report a reconfigurable optical attenuator.…”

A Nonvolatile Bipolar Optical Fiber Memory Based on Phase Change Materials

“…In this study, a spherical resonant cavity is created by discharging a single-mode optical fiber using a fiber fusion splicer, and a bipolar cell is formed by combining two information channels, as shown in Figure a. The microspheres produced through this method have antienvironmental interference, long life, and high sensitivity − and exhibit a low loss of less than 0.1 dB and a high signal-to-noise ratio of 20 dB. With a quality factor ( Q -factor) of up to 10 8 , this microsphere demonstrates exceptional accuracy in all-optical storage.…”

Fiber-Integrated All-Optical Signal Processing Device for Storage and Computing

“…Based on our previous research results, − in this paper, we propose and demonstrate an all-optical signal processing device based on GST and optical fiber, which has both memory and matrix computing capabilities. We use single-mode fiber (SMF) combined with multimode fiber (MMF) to generate a Bessel-like beam to realize multilevel modulation of GST.…”