Ellipsometer

Principle of Operation

The polarizer array, wave-plate array and CCD of the ellipsometer are arranged as shown in the figure to the right.
The transmission axis of the polarization array is rotated incrementally along the vertical direction. The wave-plate array is configured such that the its transmission axis is rotated along the horizontal direction.
As a result all the polarization information that would be obtained by rotating a polarizer or wave-plate is obtained at the CCD without rotating any elements.

The images to the lower right show examples of acquired data. The thickness and refractive index of a film can be calculated by Fourier analysis of similar 2D intensity distributions.

The basic configuration of the mechanically drive-less system is a light source, photonic crystal, and a CCD camera, the main charachteristics of which are:

  1. a high degree of miniaturization
  2. quality and precision of the transmission axis of array elements is very high
  3. high speed measurement
  4. because it is driveless it is suitable for a wide range of applications
The photonic crystal array parallel processing ellipsometer is a new paradigm in metrology.