Development of a multi-Fourier-transform interferometer: imaging experiments in millimeter and submillimeter wave...

Area of Science:

• Astrophysics
• Spectroscopy
• Interferometry

Background:

• Millimeter and submillimeter wave astronomy require advanced imaging techniques.
• Fourier-transform spectroscopy is a powerful tool for analyzing electromagnetic radiation.
• Previous theoretical work proposed a novel interferometer design for broadband imaging.

Purpose of the Study:

• To experimentally validate the multi-Fourier-transform interferometer (MuFT) for broadband imaging.
• To demonstrate the MuFT's capability in acquiring mutual coherence signals from extended sources.
• To confirm the theoretical advantages, such as large dynamic range, of the MuFT design.

Main Methods:

• Development of a Michelson-type bolometric interferometer based on a Martin-Puplett spectrometer.
• Acquisition of mutual coherence signals from an extended source in the broadband.
• Analysis of coherence data using established formulas to extract 2D source images.
• Wavenumber-resolved imaging from 5 cm⁻¹ to 35 cm⁻¹ with a 0.4 cm⁻¹ interval.

Main Results:

• Successful proof-of-concept for the MuFT's broadband imaging capabilities.
• Acquisition of mutual coherence signals for an extended source.
• Extraction of 2D source images across the 150 GHz to 1.05 THz range.
• Experimental confirmation of the MuFT's large dynamic range.

Conclusions:

• The MuFT is a viable instrument for broadband imaging in the millimeter and submillimeter range.
• The experimental results align with theoretical predictions, validating the MuFT design.
• The instrument's performance demonstrates its potential for astronomical observations and other applications requiring high-resolution spectral imaging.