Kalaga Madhav

We 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 $\approx 56\%$. For calibration of the visibility-to-pixel matrix, we use a two-input Michelson interferometer and extract the complex visibility.

1 INTRODUCTION An avalanche photodiode (APD) works in principle as a pin-diode with an internal amplification through the avalanche effect, which is based on impact ionization produced by the photo-generated charge carriers. If the amplified carriers are electrons instead of holes, the denomination of eAPD is used (Reisch 2007). Early attempts to produce focal plane arrays with the eAPD technology were conducted by ESO and Selex, nowadays Leonardo.

5 HYBRIDIZATION OF PICS AND IMAGE SENSORS The current layout of PAWS with large free-space optics for cross-dispersion and imaging onto the detector is experimental. To reduce the size of PAWS, it would be ideal to use a simple line detector arrays mounted directly to the facet of the AWG, such as the Hamamatsu ROIC 1 × 1024 $$ 1\times 1024 $$ Line Arrays (Figure 22), or the Teledyne GigE SWIR line scan camera.