DRS is the inventor and a leading developer of Blocked Impurity Band detector technology for ground, airborne and space-based observing applications and the sole developer of antimony doped silicon (Si:Sb) blocked impurity band (BIB) FPAs. Arsenic doped silicon (Si:As) and Si:Sb arrays in 128(2) pixel formats were developed by DRS for use on the Spitzer Space telescope. In the subsequent years these arrays were extended in both format and capability. 1024(2) pixel format, low flux Si:As arrays were developed for the NASA WISE mission, and Si:As and Si:Sb arrays were developed for higher flux applications such as JPL's MegaMIR camera and Cornell's FORCAST instrument for SOFIA, in both 256(2) and 1024(2) pixel array formats. Si:Sb arrays have advanced to offer similar responsivity, response uniformity, high operability and low dark currents long associated with Si:As BIB arrays but with high quantum efficiency that extends to 40 mu m, compared to only 28 mu m for Si:As. Recently, Si:Sb detector material has been further developed for low flux astronomy applications. Specifically, Si:Sb material has been grown to satisfy exceptionally low dark current requirements (such as < 0.5 e(-)/s/pixel at 5 K) for large format focal plane arrays for future infrared telescopes. This paper will focus on the characterization of this low flux Si:Sb detector material

Visible light photon counters (VLPCs) are solid-state devices providing high quantum efficiency (QE) photon detection (>88%) with photon number resolving capability and low timing jitter (similar to 250 ps). VLPC features high QE in the 0.4-1.0 mu m wavelength range, as the main photon absorption mechanism is provided by electron-hole pair generation across the silicon bandgap. In this paper, we will discuss the optical and electrical operating principles of VLPCs, and propose a range of device optimization paths that improves various aspects of VLPC for advanced quantum optics and quantum information processing experiments, both in the UV and the telecom wavelength range.

DRS Sensors & Targeting Systems, under contract to the Space Dynamics Laboratory of Utah State University, provided the focal plane detector system for NASA's Wide-field Infrared Survey Explorer (WISE). The focal plane detector system consists of two mercury cadmium telluride (MCT) focal plane module assemblies (FPMAs), two arsenic doped silicon (Si:As) Blocked Impurity Band (BIB) FPMAs, electronics to drive the FPMAs and report digital data from them, and the cryogenic and ambient temperature cabling that connect the FPMAs and electronics. The WISE Satellite was launched in late 2009 and has been a very rewarding success. In light of the recent success on orbit, there were many challenges and hurdles the DRS team had to overcome in order to guarantee the ultimate success of the instrument. This report highlights a few of the challenges that the team overcame in hopes that the information can be made available to the astronomy community for future use.

Visible light photon counters (VLPCs) offer many attractive features as photon detectors, such as high quantum efficiency and photon number resolution. We report measurements of the single-photon timing jitter in a VLPC, a critical performance factor in a time-correlated single-photon counting measurement, in a fiber-coupled closed-cycle cryocooler. The measured timing jitter is 240 ps full-width-at-half-maximum at a wavelength of 550 nm, with a dark count rate of 25 000 counts per second. The timing jitter increases modestly at longer wavelengths to 300 ps at 1000 nm, and increases substantially at lower bias voltages as the quantum efficiency is reduced.

The Blocked Impurity Band (BIB) detector technology team at DRS Sensors and Targeting Systems specializes in providing the highest performance, broadest application range of BIB detector products. These include detectors, Focal Plane Arrays (FPA), and sensor assemblies for ground, airborne and space applications. We offer flight proven low flux Si:As and Si:Sb FPAs in square formats up to 1024x1024. We also offer high-flux FPA systems for ground-based telescopes and airborne applications in several square and rectangular formats, such as 160×640 sensors for push-broom spatial-spectral imaging. NASA's Wide-field Infrared Survey Explorer mission selected DRS 1024×1024 arrays for its the 12 and 24 micron wavelength bands. The Spitzer Space Telescope utilizes DRS 128×128 Si:As and Si:Sb FPAs, and 1024×1024 Si:Sb arrays are being fabricated by DRS for an upgrade to the SOFIA FORCAST instrument. DRS is unique in providing detectors and FPAs in alternate detector materials such as Si:Sb, Si:Ga, and Si:P to optimize wavelength range vs operating temperature. Sensor assemblies include detectors or FPAs packaged with cryogenic cabling and electronics and ambient temperature drive and data acquisition electronics--fully tested, and environmentally qualified. DRS is also unique in extending its conventional BIB detector product line to include novel detector architectures for a variety of applications. Si:As detectors with avalanche gain (~40,000X) function as number-mode photon counters at visible or mid-infrared wavelengths. A recent DRS innovation is the extension of Si:As BIB detectors designs to achieve wavelength extension into the far-infrared (low THz) wavelength region. Wavelength extension to ~50 microns (6 THz) has been demonstrated, with further extension to at least ~100 microns (3 THz) in progress.

Several far-infrared (30 to 300 μm) astronomy missions and/or instruments will be proposed for the next decade. Many important astrophysical processes have signatures at these wavelengths: the peak of the spectral energy distributions of protostars and ultra-luminous galaxies falls near 100 μm; there is a wealth of biologically interesting spectral lines to be found in this range, and lines such as the 158 μm line of singly ionized carbon are important for the energy balance of the interstellar medium in our own and in external galaxies. The promise of a new generation of large format far-infrared detector arrays seems to be attainable, but getting there will require a focused development program with enough resources available to allow exploration of several paths. Development must be encouraged if we are to maximize the scientific return from future far-infrared missions. Portions of this work were carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. Astro2010 Technology Development Far-IR Detectors, Ressler et al.

The visible light photon counter (VLPC) is a very high quantum efficiency (QE, 88% at 694 nm) single photon detector in the visible wavelengths. The QE in the ultraviolet (UV) wavelenghths is poor in these devices due to absorption in the degenerate front contact. We introduce the ultraviolet photon counter (UVPC), where the QE in the near UV wavelength range (300-400 nm) is dramatically enhanced. The degenerate Si front contact of the VLPC is replaced with a Ti Schottky contact, which reduces the absorption of incident photons within the contact layer. We demonstrate a system QE of 5.3% at 300 nm and 11% at 370 nm for a UVPC with a Ti Schottky contact and a single layer MgF(2) antireflection coating.

Our group has developed the first 1024×1024 high background Si:As detector array, the Megapixel Mid-Infrared array (MegaMIR). MegaMIR is designed to meet the thermal imaging and spectroscopic needs of the ground-based and airborne astronomical communities. MegaMIR was designed with switchable capacitance and windowing capability to allow maximum flexibility. We report initial test results for the new array.

The Wide-field Infrared Survey Explorer is a NASA Midex mission launching in late 2009 that will survey the entire sky at 3.3, 4.7, 12, and 23 microns (PI: Ned Wright, UCLA). Its primary scientific goals are to find the nearest stars (actually most likely to be brown dwarfs) and the most luminous galaxies in the universe. WISE uses three dichroic beamsplitters to take simultaneous images in all four bands using four 1024×1024 detector arrays. The 3.3 and 4.7 micron channels use HgCdTe arrays, and the 12 and 23 micron bands employ Si:As arrays. In order to make a 1024×1024 Si:As array, a new multiplexer had to be designed and produced. The HgCdTe arrays were developed by Teledyne Imaging Systems, and the Si:As array were made by DRS. All four flight arrays have been delivered to the WISE payload contractor, Space Dynamics Laboratory. We present initial ground-based characterization results for the WISE arrays, including measurements of read noise, dark current, flat field and latent image performance, etc. These characterization data will be useful in producing the final WISE data product, an all-sky image atlas and source catalog.

We demonstrate a high quantum efficiency single photon detector with operating wavelength extended into the ultraviolet range (250nm–1μm). Quantum efficiency of 6% is demonstrated at 300 nm, with estimated internal efficiency of 24%.

1. ABSTRACT Photon detectors and focal plane arrays (FPAs) are fabricated at DRS from HgCdTe and silicon in many varieties. Remote sensing applications, however, may need to operate under both high and low background conditions. HgCdTe HDVIP FPAs have been measured under a variety of flux conditions and at several operating temperatures. In addition, DRS manufactures silicon detectors and FPAs that cover the spectral range from visible to the very- long-wavelength infrared (VLWIR). Large-format, VLWIR FPAs based on doped-silicon Blocked-Impurity-Band (BIB) detectors have been developed. FPAs with Si:As BIB arrays have been made in a variety of pixel formats (up to 1024 2 ) and have been optimized for low, moderate, and high infrared backgrounds. DRS uses LPE-grown SWIR, MWIR and LWIR HgCdTe material to fabricate High-Density Vertically Integrated Photodiode (HDVIP) architecture detectors. 2.5 μm, 5.3 μm and 10.5 μm cutoff detectors have been fabricated into linear arrays as technology demonstrations targeting remote sensing programs. This paper presents 320 x 6 array configuration technology demonstrations' performance of HDVIP HgCdTe detectors. Within the arrays, the detector size is 40 μm x 50 μm. The MWIR detector array has a mean quantum efficiency of 89.2 % with a standard deviation to mean ratio, σ/μ = 1.51 %. The integration time for the focal plane array (FPA) measurements is 1.76 ms with a frame rate of 557.7 Hz. NEI σ/μ = 3.0 % was measured with 100 % operability when running the array

We present a description of a new 1024×1024 Si:As array designed for ground-based use from 5 - 28 microns. With a maximum well depth of 5e6 electrons, this device brings large-format array technology to bear on ground-based mid-infrared programs, allowing entry to the megapixel realm previously only accessible to the near IR. The multiplexer design features switchable gain, a 256×256 windowing mode for extremely bright sources, and it is two-edge buttable. The device is currently in its final design phase at DRS in Cypress, CA. We anticipate completion of the foundry run in October 2005. This new array will enable wide field, high angular resolution ground-based follow up of targets found by space-based missions such as the Spitzer Space Telescope and the Widefield Infrared Survey Explorer (WISE).

Abstract : Boeing and Lawrence Semiconductor Research Laboratory are developing high-performance gallium-doped-silicon (Si: Ga) impurity-band-conduction material and Blocked-Impurity-Band (BIB) detectors. We build on a strong technology base in arsenic-doped silicon (Si:As) material and BIB detector technology. Si:As large-format focal plane arrays offer background-limited infrared performance (^28 micrometers cut-off wavelength) and excellent pixel operability and uniformity to many defense and space imaging and spectroscopy applications. Application of Si:As BIB detectors to long-lifetime missions is restricted by operating temperature (^10 K) below the range of available cooler technologies. The development of a Si:Ga option, with several degrees higher operating temperature, is intended to ease this restriction. The Si:Ga cut-off wavelength (^18 to 20 micrometers) is suitable for many ground- and space-based applications. Known Si:Ga material development issues have been circumvented and detector-quality Si:Ga material and initial front- and back-illuminated BIB detector structures have been prepared and evaluated. We report dark current, quantum yield, and spectral response for prototype devices and discuss material and detector improvement directions.