An angle-scanned cryogenic Fabry-Pérot interferometer for far-infrared astronomy

Area of Science:

• Astrophysics
• Optical Engineering
• Spectroscopy

Background:

• Far-infrared detectors in space telescopes are limited by photon noise.
• High-resolution spectroscopy requires restricting the spectral bandpass.
• Fabry-Pérot interferometers (FPIs) are used for high-resolution spectroscopy.

Purpose of the Study:

• To present a novel FPI design for space-based spectroscopy.
• To simplify the cryomechanical design, actuation, and metrology of tunable FPIs.
• To demonstrate wavelength tuning by scanning the angle of incidence.

Main Methods:

• Designed a novel FPI utilizing a high refractive index etalon.
• Tuned the resonant wavelength by scanning the angle of incidence.
• Simulated spectral response as a function of incident angle.

Main Results:

• Successfully realized and tested the novel FPI instrument.
• Observed spectral response agrees well with theoretical simulations.
• The angle-tuning method simplifies instrument design and operation.

Conclusions:

• The angle-tuned FPI offers a simplified and effective approach for background-limited, high-resolution spectroscopy.
• This novel design is suitable for cryogenically cooled space telescopes.
• Further development can enhance capabilities for astronomical observations.