2017/07/07 by S. J. C. Yates, Yates, Stephen J. C., A. Baryshev +19 · 1 citation
Engineering · Physics and Astronomy · #FOS: Physical sciences #Instrumentation and Detectors (physics.ins-det) #Instrumentation and Methods for Astrophysics (astro-ph.IM) #Photonic and Optical Devices #Superconducting and THz Device Technology #Terahertz technology and applications
paper · pdf · doi:10.48550/arxiv.1707.02142
openalex publication_date 2017/07/07 · openalex created_date 2022/10/01 · openalex updated_date 2026/07/28
Large ultra-sensitive detector arrays are needed for present and future\nobservatories for far infra-red, submillimeter wave (THz), and millimeter wave\nastronomy. With increasing array size, it is increasingly important to control\nstray radiation inside the detector chips themselves, the surface wave. We\ndemonstrate this effect with focal plane arrays of 880 lens-antenna coupled\nMicrowave Kinetic Inductance Detectors (MKIDs). Presented here are near field\nmeasurements of the MKID optical response versus the position on the array of a\nreimaged optical source. We demonstrate that the optical response of a detector\nin these arrays saturates off-pixel at the \∼-30 dB level compared to the\npeak pixel response. The result is that the power detected from a point source\nat the pixel position is almost identical to the stray response integrated over\nthe chip area. With such a contribution, it would be impossible to measure\nextended sources, while the point source sensitivity is degraded due to an\nincrease of the stray loading. However, we show that by incorporating an\non-chip stray light absorber, the surface wave contribution is reduced by a\nfactor >10. With the on-chip stray light absorber the point source response\nis close to simulations down to the \∼-35 dB level, the simulation based on\nan ideal Gaussian illumination of the optics. In addition, as a crosscheck we\nshow that the extended source response of a single pixel in the array with the\nabsorbing grid is in agreement with the integral of the point source\nmeasurements.\n