Angle measurement using surface-plasmon-resonance heterodyne interferometry: a new method

A novel optical method for high-resolution angle measure- ment based on surface plasmon resonance (SPR) is presented. The phase difference between p and s polarization states when SPR takes place is very sensitive to the angle of incidence. Heterodyne interferom- etry is employed to measure this phase difference and thus to measure small angles. The feasibility of this method is demonstrated. The mea- surement resolution of 2310 25 deg can be achieved by this method.