Stationary Fourier-transform spectrometer

Area of Science:

• * Optical Spectroscopy
• * Interferometry
• * Spectrometer Design

Background:

• * Traditional interferometers often require beam splitters and moving parts, limiting their robustness and applicability.
• * Characterizing spectrometers with uncollimated light presents unique challenges for performance analysis.

Purpose of the Study:

• * To investigate the performance and characteristics of a novel stationary interferometric double-mirror spectrometer.
• * To evaluate the spectrometer's capabilities with uncollimated light and various radiation sources.
• * To demonstrate methods for enhancing the spectrometer's dynamic range and resolving power.

Main Methods:

• * Fabrication of a stationary interferometer without a beam splitter or moving components.
• * Measurement of spectra from diverse radiation sources, including mercury lamps and diode lasers.
• * Application of background subtraction techniques to mitigate detection nonuniformity.

Main Results:

• * Measured interferogram visibilities align with theoretical predictions for both slit and circular apertures.
• * Background subtraction significantly improved the spectrometer's dynamic range (~80 dBm with a mercury lamp) and resolving power.
• * A maximum resolving power of 1600 was achieved when measuring diode laser spectra.

Conclusions:

• * The developed interferometric spectrometer effectively analyzes spectra from various sources using uncollimated light.
• * The instrument demonstrates high dynamic range and resolving power, particularly after background subtraction.
• * This spectrometer is suitable for applications such as monitoring laser wavelengths and recording temporally variant, wideband radiation sources.