Table 1 Comparison of multiple mechanisms for modulation
From: Ultracompact Nanophotonics: Light Emission and Manipulation with Metasurfaces
| Modulation mechanism | Active component | Operation spectrum | Modulation speed | Advantages | Limitations | Refs |
|---|---|---|---|---|---|---|
| Mechanical tunability |
Au/PDMS Cu w/o substrate Al/PDMS Au/PDMS Al/PDMS |
Vis Microwave Vis Vis MIR | s to ms scale | Simple, low cost, extensive tuning range | Modulation speed, stability, reliability | [52,53,54,55,56] |
| Thermal tunability |
VO2/Au/sapphire Au/SiO2/VO2/Si VO2/sapphire VO2/Si hBN/VO2/quartz |
NIR to MIR mm μm MIR MIR | ms scale | Reversible, low transition temperature | Low heating speed, energy loss | [65,66,67,68,69] |
|
GST/Al/Si Al/GST/Al/Si Au/GST/CaF2 ZnS/SiO2-GST-ZnS/SiO2/quartz GST/CaF2 |
NIR to MIR NIR to MIR NIR to MIR Vis NIR to MIR | ms to fs scale | Efficient, stable, nonvolatile | Cooling rate limited, energy loss | [72,73,74,75,76] | |
| Optical tunability |
nGaAs/AlGaAs/epoxy/sapphire Al/Si/SiO2 Si/sapphire All Si | THz | fs to ps scale | Ultrafast speed, nonvolatile | Power consumption, modulation depth | [78,79,80,81] |
| Electrical tunability |
Au/ITO/SiO2/Au/quartz ITO/Au/SiNx/Si/Au Au/Al2O3/ITO/Au/quartz Au/Al2O3/ITO/Au Si/Al2O3/ITO/Au/Si Au/HAOL/ITO/Al2O3/Au/PCB |
Vis to MIR NIR to MIR NIR THz THz NIR | μs scale | Fast speed, good stability | Power consumption, modulation depth | [32, 35,36,37, 98, 99] |
|
ITO/Si/fused silica Au/Al2O3/ITO/Si |
NIR NIR | μs scale | Fast speed, good stability | Power consumption, modulation depth | [38, 39] |