Table 1.
ONE | TWO | |
---|---|---|
Distance precision | > 1.5 nm | < 0.5 nm |
Photon budget | 10,000 photons | 100 photons |
Range of distance | unlimited | 2 ~ 8 nm |
Frame of reference | absolute position (two or three dimensional) | relative distance or orientation (one dimensional) |
Requirement for low drift and low vibration equipment | very high | low |