Design of a 1k pixel Ge:Sb focal-plane array for far-IR astronomy

Development of large format, far infrared focal-plane arrays has been identified as a pressing need for future astronomical instruments. In particular, array sizes as large as 128x128 with sensitivities equal to or better than 10-18 W/√Hz are the goals to be achieved within the next fifteen years. As part of our continuing effort to further this technology, we are developing a 32x32 Ge:Sb photoconductor FPA with a CTIA cryogenic readout multiplexer. A new, layered-hybrid architecture is employed to block the readout glow, improve heat dissipation and temperature uniformity across the array, and alleviate the potential problems associated with the large CTE mismatch between the Ge detector and the Si readout. This is the first 1k-pixel photoconductor FPA of its kind and is meant to be a pathfinder for future large format FPAs. Based on the test results of a prototype 2x16 Ge:Sb array of similar design, we expect the sensitivity of this FPA to be as low as 10-18 W/√Hz. This paper presents the design, characteristics, and the expected performance of this array.

[1]  Erick T. Young,et al.  Mission Concept for the Single Aperture Far-Infrared (SAFIR) Observatory , 2004, SPIE Astronomical Telescopes + Instrumentation.

[2]  E. E. Haller,et al.  Far Infrared Photoconductors: Recent Advances and Future Prospects , 2002 .

[3]  David L. Sisson,et al.  A low noise 2 × 16 Ge:Sb focal-plane array: Paving the way for large format FPAs for far IR astronomy , 2007 .

[4]  Eugene E. Haller,et al.  High performance antimony-doped germanium photoconductors , 1996 .

[5]  Rainer Hoenle,et al.  Far-infrared photoconductors for Herschel and SOFIA , 2003, SPIE Astronomical Telescopes + Instrumentation.

[6]  Jam Farhoomand,et al.  Characterization of SBRC-190: a multi-gain, cryogenic readout multiplexer for IR detector arrays , 2003, SPIE Astronomical Telescopes + Instrumentation.

[7]  Olivier Boulade,et al.  Submillimeter bolometers arrays for the PACS/Herschel spectro-photometer , 2004, SPIE Astronomical Telescopes + Instrumentation.

[8]  Jordana Bandaru,et al.  Liquid phase epitaxial growth and characterization of germanium far infrared blocked impurity band detectors , 2001 .

[9]  Dominic J. Benford,et al.  Thousand-Element Multiplexed Superconducting Bolometer Arrays , 2002 .

[10]  James F. Asbrock,et al.  Specification and design of the SBRC-190: a cryogenic multiplexer for far-infrared photoconductor detectors , 2003, SPIE Astronomical Telescopes + Instrumentation.

[11]  Marcia J. Rieke,et al.  On-orbit performance of the MIPS instrument , 2004, SPIE Astronomical Telescopes + Instrumentation.

[12]  Dominic J. Benford,et al.  New Concepts for Far-Infrared and Submillimeter Space Astronomy , 2004 .

[13]  David L. Sisson,et al.  Viability of layered-hybrid architecture for far IR focal-plane arrays , 2008 .

[14]  Erick T. Young,et al.  Test results for the SIRTF far-infrared array module , 1995, Defense, Security, and Sensing.

[15]  G. G. Stokes "J." , 1890, The New Yale Book of Quotations.

[16]  George H. Rieke,et al.  Single aperture far-infrared observatory (SAFIR) , 2003, SPIE Astronomical Telescopes + Instrumentation.

[17]  Norbert Geis,et al.  The Photodetector Array Camera & Spectrometer (PACS) for the Herschel Space Observatory , 2003, SPIE Astronomical Telescopes + Instrumentation.

[18]  Detector Needs for Long Wavelength Astrophysics , 2002 .

[19]  Jam Farhoomand A novel design for direct-hybrid far-infrared photoconductor arrays , 2004, SPIE Astronomical Telescopes + Instrumentation.

[20]  Albrecht Poglitsch,et al.  Characterization of high- and low-stressed Ge:Ga array cameras for Herschel's PACS instrument , 2004, SPIE Astronomical Telescopes + Instrumentation.

[21]  Paul W. Richards Bolometric Detectors for Space Astrophysics , 2002 .

[22]  Toshio Matsumoto Large aperture cool telescope mission: SPICA , 2003, SPIE Astronomical Telescopes + Instrumentation.

[23]  Hidehiro Kaneda,et al.  Far-Infrared Surveyor: design, operation, and performance , 2004, SPIE Astronomical Telescopes + Instrumentation.

[24]  Dominic Benford,et al.  CALISTO: the Cryogenic Aperture Large Infrared Space Telescope Observatory , 2008, Astronomical Telescopes + Instrumentation.

[25]  Erick T. Young Progress on readout electronics for far-infrared arrays , 1994, Defense, Security, and Sensing.

[26]  Jeffrey W. Beeman,et al.  GaAs LPE GROWTH CENTRIFUGE - A NOVEL FACILITY TO PRODUCE HIGH PURITY GaAs MATERIAL , 2002 .

[28]  Harvey S. Moseley,et al.  An Engineering Concept and Enabling Technologies for a Large Single Aperture Far-Infrared Observatory (SAFIR) , 2003, SPIE Astronomical Telescopes + Instrumentation.

[29]  Hidehiro Kaneda,et al.  Development of a gallium-doped germanium far-infrared photoconductor direct hybrid two-dimensional array. , 2003, Applied optics.

[30]  Jam Farhoomand,et al.  The first look at SB349, a 32×32 CTIA readout multiplexer for far IR focal-plane arrays , 2007, SPIE Optical Engineering + Applications.

[31]  Takao Nakagawa,et al.  Preflight performance measurements of a monolithic Ge:Ga array detector for the Far-Infrared Surveyor onboard ASTRO-F , 2004, SPIE Astronomical Telescopes + Instrumentation.