Infrared single mode chalcogenide glass fiber for space

Area of Science:

• Astronomy and Astrophysics
• Materials Science
• Optical Engineering

Background:

• Nulling interferometry is crucial for detecting exoplanets via their infrared emissions.
• Achieving a perfect wavefront is essential for the success of nulling interferometry.
• Wavefront errors must be corrected before light beams are combined in the interferometer.

Purpose of the Study:

• To develop and optically characterize infrared-transmitting chalcogenide glasses and mid-infrared (mid-IR) optical fibers.
• To assess the suitability of these materials and fibers for wavefront error filtering in nulling interferometry.
• To enable precise detection of exoplanetary signals for missions like DARWIN.

Main Methods:

• Development of core-cladding chalcogenide fibers using two distinct manufacturing techniques.
• Optical characterization of the developed chalcogenide glasses and fibers.
• Testing single-mode guidance capabilities at 10.6 µm using step-index fibers.

Main Results:

• Successful development of chalcogenide glasses and mid-IR guiding optical fibers.
• Demonstration of wavefront error filtering using single-mode waveguides.
• Two types of step-index fibers made with Te(2)As(3)Se(5) glasses provide single-mode guidance at 10.6 µm.

Conclusions:

• Chalcogenide optical fibers are effective in filtering wavefront errors, producing a near-perfect plane wavefront.
• These fibers are suitable for nulling interferometry, enhancing the detection of weak infrared signals from exoplanets.
• The developed Te(2)As(3)Se(5) fibers offer a promising solution for future planet-finding missions requiring high-precision optical measurements.