Advanced Detectors, Systems, & Nanoscience
Broadband Detectors for On-Sky Observation
On-sky observations with broadband delta-doped arrays were planned as part of an effort funded by NASA’s Strategic Astrophysics Technology (SAT). Delta-doped p-channel devices were previously developed in collaboration with Lawrence Berkeley National Laboratory (LBNL). These detectors were processed using MDL’s large-capacity silicon MBE, and the broadband coating used was developed using ALD to maximize the response over the required range (320–1000 nm). This is the baseline detector for an Explorer-Orion mission concept, and on-sky observation is a necessary step for laboratory devices to showcase their capabilities and demonstrate their viability for future missions. Thus, three prototype LBNL detectors were delivered to Arizona State University for testing at Arizona’s Kitt Peak National Observatory.
MDL is also working with Semiconductor Technologies Associates (STA) and Teledyne DALSA to develop delta-doped n-channel detectors with similar broadband performance for the 200-inch Hale Telescope at Caltech’s Palomar Observatory. These 4-megapixel arrays will be primarily used for the guide and focus functions in WaSP (Wafer Scale Prime), a replacement instrument for the Hale Telescope’s current Large Format Camera. Due to their extended response in the blue and red ends of the spectrum, the arrays allow additional capabilities that can be used by observers.