Polarization Separated Phase Shifted Interferometer

Interferometry is a well-established field of measurement used for various applications such as studying surface topographies. Yet, the traditional interferometers, despite their precision, harbor a significant downside ─ the need for moving parts ─ which raises concerns about mechanical failures and long-term durability. Consequently, there is substantial demand for innovative solutions capable of achieving the same or superior data quality without the constraints of precise mechanical parts. The majority of conventional interferometers rely on intricate mechanical setups to regulate beam interference and derived measurements. This approach, while effective under well-calibrated conditions, often introduces issues of mechanical wear and unpredictable errors resulting from physical movements. Furthermore, conventional methods may require frequent maintenance and calibration, instigating a demand for innovative interferometry techniques that bypass these troubles.

Technology Description

This technology is a phase-shifted interferometer capable of producing interferograms without the need for moving parts. It operates using a phase shifter, such as an electro-optic phase modulator, to alter the relative phase between the sample and reference beams. These beams are then turned into orthogonal polarization states, coupled through a common path, and sent into separate arms via a polarizing beam splitter (PBS). The beams' polarization states are altered by quarter-wave plates in their respective arms to allow coupling out of the PBS to a detector via a 45° linear polarizer. This technology stands out from the rest because of its capability to generate effective output without required mechanical motion, thus eliminating potential points of failure from wear and tear. Moreover, it leverages a unique technique of polarizing and phase shifting the beams, providing precise with controlled relative phases. This technique results in a detailed mapping of surface topography to boost its efficiency and precision in topography-mapping applications.