Characterization of Teledyne HAWAII-4RG-15 Infrared Detector Arrays
Abstract
With funding from NSF, the University of Hawaii Institute for Astronomy, in partnership with Teledyne Imaging Sensors, LLC, have, over the past decade, developed the HAWAII-4RG-15 near infrared detector arrays with a cut-off wavelength of 2.5 micro-meters. The "R" in the name indicates the presence of reference pixels, the "G" stands for guide-window mode, and the "15" indicates the pixel size in micro-meters. These devices are usually abbreviated as H4RG-15.
The H4RG-15 detector arrays can operate with up to 64 output amplifiers, but in our testing program, they were operated by a single Teledyne SIDECAR ASIC with 32 signal channels. In addition to the frame of 4 rows and columns of reference pixels that the older H2RG devices are using, the H4RG-15 provides reference pixels that can be read out interleaved with the IR-sensitive science pixels. In our testing, we routinely used the interleaved reference pixels, leading to a full-frame read-out time of 5.4 s. As part of the development program, Teledyne had produced three near-science-grade detector arrays with two different passivation processes. One of these, referred to as PV1 here, turned out to be clearly superior with respect to persistence effects. The telescope tests of the best (PV1) device were done using the ULB-Cam test system restricted to the J and H bands. These tests showed that under conditions of low electronic pickup noise, the use of the interleaved reference pixels does not offer an advantage over the use of the frame reference pixels. Most importantly, the telescope tests with standard dithering data acquisition showed no noticeable detector persistence in the broad J and H filters. The laboratory tests showed only minimal, short duration persistence on the PV1 device, and moderate persistence on the PV2 devices. For both flavors of detector material, localized persistence near bad pixel areas was noted and my be caused by internal stress of the detector material. The detector arrays show non-linear photometric response near the saturation level due to the changes in photodiode capacitance with remaining bias voltage. This non-linearity can be fitted with a polynomial and corrected for.- Publication:
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American Astronomical Society Meeting Abstracts #234
- Pub Date:
- June 2019
- Bibcode:
- 2019AAS...23410302H