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Ultra-Sensitive Transition-Edge Sensors (TESs) for Far-IR/Submm Space-Borne SpectroscopyWe have built surface micromachined thin-film metallized Si(x)N(y) optical absorbers for transition-edge sensors (TESs) suitable for the Background - Limited far-IR/Submm Spectrograph (BLISS). BLISS is a broadband (38 micrometers - 433 micrometers), grating spectrometer consisting of five wavebands each with a modest resolution of R (is) approx. 1000. Because BLISS requires the effective noise equivalent power (NEP) of the TES to be below 10 (exp 19) W/Hz(exp 1/2), our TESs consist of four long (1000 micrometers), narrow (0.4 micrometers ), and thin (0.25 micrometers ) Si(x) N(y) support beams that reduce the thermal conductance G between the substrate and the optical absorber. To reduce the heat capacity of the absorber and make the response time tau fast enough for BLISS, our absorbers are patterned into a mesh geometry with a fill factor of less than 10%. We use a bilayer of Ti/Au to make the effective impedance of the absorber match the impedance of the incoming radiation for each band. Measurements of the response time of the metallized absorbers to heat pulses show that their heat capacity exceeds the predictions of the Debye model. Our results are suggestive that the surface of the low pressure chemical vapor deposition (LPCVD) Si(x)N(y) used in the absorbers' construction is the source of microstates that dominate the heat capacity.

Document ID
20150006898
Document Type
Conference Paper
External Source(s)
Authors
Kenyon, M. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Day, P. K. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Bradford, C. M. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Bock, J .J. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Leduc, H. G. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Date Acquired
April 29, 2015
Publication Date
July 19, 2011
Subject Category
Astronomy
Instrumentation and Photography
Meeting Information
International Workshop on Low Temperature Detectors (LTD)(Heidelberg)
Distribution Limits
Public
Copyright
Other
Keywords
far-IR spectrometer
heat capacity
submillimeter spectrometer
transition-edge sensor