Backscattering Mueller-matrix photopolarimeter with nonreciprocal polarizing-analyzing optics

Area of Science:

• Optics and Photonics
• Materials Science

Background:

• Measuring the full 16 elements of a backscattering Mueller matrix requires specialized polarimetry.
• Nonreciprocal optical elements are necessary to differentiate forward and backward light paths.

Purpose of the Study:

• To present a novel return-path polarimeter design for complete backscattering Mueller matrix measurement.
• To achieve nonreciprocity using Faraday cells to alter optical element behavior for incident and backscattered beams.

Main Methods:

• Utilized a return-path polarimeter configuration.
• Incorporated Faraday cells to create apparent differences in the rotation speed of a quarter-wave retarder for incident and backscattered light.
• Ensured nonreciprocal polarizing-analyzing optics.

Main Results:

• Successfully measured all 16 elements of the backscattering Mueller matrix.
• Achieved performance comparable to a previously reported single-path polarimeter.
• Demonstrated the effectiveness of using Faraday cells for nonreciprocity.

Conclusions:

• The described return-path polarimeter design effectively measures backscattering Mueller matrices.
• This technique has potential applications in polarization lidar and advanced surface characterization, including rough anisotropic surfaces.