Cascaded interferometric imaging spectrometer.

Area of Science:

• Optical instrumentation
• Spectroscopy
• Astrophysical observation

Background:

• Fabry-Perot interferometers are crucial for spectral analysis.
• Order sorting is essential for unambiguous spectral data.
• Existing Fourier transform spectrometer (FTS) and grating instruments have limitations in speed and field of view.

Purpose of the Study:

• To introduce a novel method for order sorting a Fabry-Perot interferometer.
• To demonstrate the applicability of this method across various wavelengths, specifically in the 5-25 micrometer band.
• To evaluate the performance and advantages of this new instrument concept for imaging spectroscopy.

Main Methods:

• Utilizing a Fourier transform spectrometer (FTS) in tandem with a Fabry-Perot interferometer for order sorting.
• Developing a model instrument response to demonstrate the order-sorting mechanism.
• Comparing the performance against grating and standard FTS instruments under noise-limited conditions.

Main Results:

• The proposed method achieves effective order sorting for Fabry-Perot interferometers.
• The instrument concept allows for a large bandwidth, wide field of view, and high transmission efficiency.
• The new system demonstrates a speed advantage over standard FTS instruments and grating instruments under specific conditions.

Conclusions:

• The novel tandem FTS-Fabry-Perot interferometer offers a powerful technique for imaging spectroscopy.
• Its attributes are particularly beneficial for mapping large astronomical sources.
• The instrument provides a significant speed improvement, making it valuable for background and detector noise-limited observations.