Publications by authors named "Abani S Nayak"
A fiber-connectorized K-band integrated-optics two-telescope beam combiner was developed for long-baseline interferometry at the CHARA telescope array utilizing the ultrafast laser inscription (ULI) technique. Single-mode waveguide insertion losses were measured to be ∼1.1 over the 2-2.
View Article and Find Full Text PDFWe have built and characterized, to our knowledge, the first six-telescope discrete beam combiner (DBC) for stellar interferometry in the astronomical J-band. It is the DBC with the largest number of beam combinations and was manufactured using ultrafast laser inscription in borosilicate glass, with a throughput of ≈56. For calibration of the visibility-to-pixel matrix, we use a two-input Michelson interferometer and extract the complex visibility.
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- The study presents initial results from a four-telescope integrated optics discrete beam combiner (DBC) tested at the William Herschel Telescope, designed to improve astronomical observations.
- The DBC, created using ultrafast laser inscription on a single substrate, processes light from stars like Vega and Altair at the H-band (1.6 µm) while utilizing a deformable mirror for efficient light injection.
- The results indicated that the measured visibility amplitudes and closure phases were affected by a significant dispersion from expected values, primarily due to a low signal-to-noise ratio, marking an initial step toward validating DBC for long-baseline interferometry.