Ultracompact Si-GST Hybrid Waveguides for Nonvolatile Light Wave Manipulation

Silicon Nitride Photonics for the Near-Infrared

“…These materials have been exploited for a variety of tunable photonic applications ranging from smart windows [72] to metamaterials [73]. The combination of SiN waveguides and PCMs can lead to ultrafast non volatile re-configurable technology for optical communications applications [74], [75]. A large scale fabrication process for re-configurable integrated devices based on phase change materials has been demonstrated ( Fig.13).…”

Feasibility study of a Ge2Sb2Te5-clad silicon waveguide as a non-volatile optical on-off switch

“…In this work, the refractive indices of silicon and silica at operating wavelength at 1.55 µm are taken as n (Si) = 3.481, n (SiO 2 ) = 1.44468. The complex refractive indices of GST, measured by using the VASE ellipsometer, are taken as n (Amorphous-GST) = 4.03654 + j0.03746, n (Crystalline-GST) = 6.49615 + j1.0655, respectively [9,13].…”

“…Although GST states can be changed by optical, electrical and thermal approaches, however, in our switch design, we have assumed that the state of the GST is changed from its initial amorphous to the crystalline state by thermal annealing. This crystallization can be achieved by heating GST above the glass transition temperature and then slowly cooling down [9].…”

“…In addition to that, unlike other electro-optic materials, GST possesses the self-holding feature, which means it requires energy only to switch from one state to another, but continuous supply of energy is not needed to maintain a given state. A recent work also reports on the practical implementation of asymmetric Mach-Zehnder switch using GST clad silicon rib waveguide [9].…”

Miniature Multilevel Optical Memristive Switch Using Phase Change Material

“…The phase change is non-volatile and therefore no power is required to keep the state. In addition to the electrical resistance contrast, a pronounced change in the optical property, including refractive index, extinction coefficient, and reflectance, also occurs in PCMs during the phase transition [14,15]. Such features have led to the development of on-chip non-volatile photonic applications, such as nanopixel display [16,17], photonic synapse [18,19], optical computing [20], and optical switching [21][22][23][24].…”