Single-pulse, Fourier-transform spectrometer having no moving parts

Area of Science:

• Optics and Photonics
• Spectroscopy
• Instrument Design

Background:

• Traditional Fourier-transform spectrometers often rely on moving parts for path difference modulation.
• Developing instruments with no moving parts is crucial for enhanced stability and reduced complexity.
• Polarization-based techniques offer alternative methods for optical path difference generation.

Purpose of the Study:

• To design and demonstrate a polarizing Fourier-transform spectrometer (P-FTS) that eliminates the need for moving mechanical components.
• To utilize spatial variation of polarization states for interferogram generation.
• To achieve rapid spectral acquisition from a single light pulse.

Main Methods:

• Incorporation of a Wollaston prism to create orthogonally polarized beams with a spatially varying path difference.
• Utilizing the aperture of the instrument to encode the path difference spatially.
• Employing a charge-integrating linear detector array for simultaneous interferogram acquisition.

Main Results:

• The instrument successfully generated an interferogram in the spatial domain by leveraging the Wollaston prism.
• Simultaneous sampling of the entire interferogram was achieved using the linear detector array.
• A complete spectrum was obtained from a single pulse of light, demonstrating the instrument's capability.

Conclusions:

• The developed polarizing Fourier-transform spectrometer offers a robust, no-moving-parts alternative for spectral analysis.
• This design enables high-speed spectral acquisition, suitable for transient events.
• Spatial encoding of the interferogram simplifies instrument design and enhances operational stability.