An apparatus for and a method of amplifying Faraday or Voigt rotation by passing light through a sample many times using multiple internal reflections and successive mirrored chambers that repeatedly send the light back through the sample. The sample is placed in a sample chamber that is adjacent to an optical amplifier chamber, and the optical amplifier chamber is adjacent to one or more additional chambers. The sample has a magnetic field applied thereto. The sample chamber receives light from a light source. The light reflects within the sample chamber and the sample to accumulate rotation of the light. The sample chamber transmits the light to the optical amplifier chamber. The optical amplifier chamber transmits the light to the additional chambers and reflects the light back to the sample where the light undergoes further rotation. Each one of the additional chambers transmits the light to the next additional chamber and reflects the light back to a previous chamber.