Related Experiment Video
Updated: Jun 12, 2026
12:14
The Generation of Higher-order Laguerre-Gauss Optical Beams for High-precision Interferometry
Published on: August 12, 2013
Tri-coupler geometries for achromatic nulling interferometry in the near-infrared
Optics Express
|June 11, 2026
Summary
Astrophotonics advances exoplanet detection using novel three-waveguide (tri-coupler) photonic beam combiners. These devices offer improved starlight suppression and exoplanet throughput for next-generation telescopes.
Area of Science:
- Astrophotonics and Optical Instrumentation
- Exoplanet Detection and Characterization
Background:
- Astrophotonics enables advanced astronomical instruments with integrated photonic circuits.
- Nulling interferometry requires efficient beam combination to suppress starlight for exoplanet detection.
Purpose of the Study:
- To compare the simulated performance of three-waveguide (tri-coupler) photonic beam combiners for broadband operation.
- To evaluate exoplanet throughput, starlight attenuation, and fabrication tolerance of different tri-coupler designs.
Main Methods:
- Simulated performance analysis of two evanescent tri-couplers and a multimode interference (MMI) coupler.
- Evaluation across the 1.5-1.8 µm wavelength band.
- Assessment of key performance metrics including exoplanet throughput and starlight attenuation.
Main Results:
- All tri-couplers achieved >40 dB starlight attenuation over a ≥270 nm bandwidth.
- Tapered tri-couplers and MMI couplers demonstrated >85% exoplanet throughput, outperforming the standard tri-coupler.
- The tapered tri-coupler achieved the highest total throughput (~96% including component losses) and offered tunable sensing capabilities.
Conclusions:
- Tapered tri-couplers and MMI couplers are promising for broadband nulling interferometry.
- The MMI coupler exhibits superior tolerance to fabrication errors, enhancing practical applicability.
- Future integrated photonic designs will aim to optimize throughput, attenuation, and sensing performance simultaneously.
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