An infrared integrated optic astronomical beam combiner for stellar interferometry at 3-4 microm

Area of Science:

• Photonics and Optical Engineering
• Astronomy Instrumentation

Background:

• Interferometric combiners are crucial for astronomical observations, enabling higher resolution by combining light from multiple telescopes.
• Existing combiners often face limitations in terms of size, stability, and operational wavelength.
• The L-band (3-4 micrometers) is significant for astronomical studies, including those of exoplanets and star formation.

Purpose of the Study:

• To design and fabricate integrated-optic interferometric combiners for L-band astronomical applications.
• To demonstrate the feasibility of on-chip fringe scanning for improved interferometric stability.
• To achieve white light fringe production using novel integrated-optic designs.

Main Methods:

• Design and fabrication of two-beam and three-beam interferometric combiners.
• Utilized titanium-indiffused, x-cut lithium niobate substrates for device realization.
• Integrated electro-optic modulators for on-chip fringe scanning.
• Coupled the combiner with an on-chip Y-splitter for white light fringe generation.

Main Results:

• Successfully designed and fabricated integrated-optic interferometric combiners for L-band operation.
• Demonstrated on-chip electro-optic fringe scanning capabilities within the devices.
• Produced clear white light fringes in a laboratory setting using the two-beam combiner and Y-splitter.

Conclusions:

• The developed integrated-optic combiners represent a novel advancement for L-band astronomical interferometry.
• On-chip fringe scanning offers a compact and efficient method for phase control in interferometers.
• These devices pave the way for more accessible and potentially more powerful astronomical interferometric systems.