The AzTEC mm-Wavelength Camera

AzTEC is a mm-wavelength bolometric camera utilizing 144 silicon nitride micromesh detectors. Herein we describe the AzTEC instrument architecture and its use as an astronomical instrument. We report on several performance metrics measured during a three month observing campaign at the James Clerk Maxwell Telescope, and conclude with our plans for AzTEC as a facility instrument on the Large Millimeter Telescope.Comment: 13 pages, 15 figures, accepted for publication in Monthly Notice

High-impedence NbSi TES sensors for studying the cosmic microwave background radiation

Precise measurements of the cosmic microwave background (CMB) are crucial in cosmology, because any proposed model of the universe must account for the features of this radiation. Of all CMB measurements that the scientific community has not yet been able to perform, the CMB B-mode polarization is probably the most challenging from the instrumental point of view. The signature of primordial gravitational waves, which give rise to a B-type polarization, is one of the goals in cosmology today and amongst the first objectives in the field. For this purpose, high-performance low-temperature bolometric cameras, made of thousands of pixels, are currently being developed by many groups, which will improve the sensitivity to B-mode CMB polarization by one or two orders of magnitude compared to the Planck satellite HFI detectors. We present here a new bolometer structure that is able to increase the pixel sensitivities and to simplify the fabrication procedure. This innovative device replaces delicate membrane-based structures and eliminates the mediation of phonons: the incoming energy is directly captured and measured in the electron bath of an appropriate sensor and the thermal decoupling is achieved via the intrinsic electron-phonon decoupling of the sensor at very low temperature. Reported results come from a 204-pixel array of Nb$_{x}$Si$_{1-x}$ transition edge sensors with a meander structure fabricated on a 2-inch silicon wafer using electron-beam co-evaporation and a cleanroom lithography process. To validate the application of this device to CMB measurements, we have performed an optical calibration of our sample in the focal plane of a dilution cryostat test bench. We have demonstrated a light absorption close to 20% and an NEP of about 7$\times10^{-16}$ W/$\sqrt{Hz}$, which is highly encouraging given the scope for improvement in this type of detectors.Comment: 6 pages, 10 figures. arXiv admin note: text overlap with arXiv:1005.0555 by other author

Instrument, Method, Brightness and Polarization Maps from the 2003 flight of BOOMERanG

We present the BOOMERanG-03 experiment and maps of the Stokes parameters I, Q, U of the microwave sky obtained during a 14 day balloon flight in 2003. Three regions of the southern sky were surveyed: a deep survey (~ 90 square degrees) and a shallow survey (~ 750 square degrees) at high Galactic latitudes (both centered at RA ~ 5.5 h, dec ~ -45 deg) and a survey of ~ 300 square degrees across the Galactic plane at RA ~ 9.1 h, dec ~ -47 deg. All three surveys were carried out in three wide frequency bands centered at 145, 245 and 345 GHz, with an angular resolution of ~ 10'. The 145 GHz maps of Stokes I are dominated by Cosmic Microwave Background (CMB) temperature anisotropy, which is mapped with high signal to noise ratio. The measured anisotropy pattern is consistent with the pattern measured in the same region by BOOMERanG-98 and by WMAP. The 145 GHz maps of Stokes Q and U provide a robust statistical detection of polarization of the CMB when subjected to a power spectrum analysis. This amplitude of the polarization is consistent with that of the CMB in the $\Lambda$CDM cosmological scenario. At 145 GHz, in the CMB surveys, the intensity and polarization of the astrophysical foregrounds are found to be negligible with respect to the cosmological signal. At 245 and 345 GHz we detect ISD emission correlated to the 3000 GHz IRAS/DIRBE maps, and give upper limits for any other non-CMB component. We also present intensity maps of the surveyed section of the Galactic plane. These are compared to monitors of different interstellar components, showing that a variety of emission mechanisms is present in that region.Comment: see http://oberon.roma1.infn.it/boomerang/b2k and http://cmb.phys.cwru.edu/boomerang/ for a high resolution versio

Lumped element Kinetic Inductance Detectors

Kinetic Inductance Detectors (KIDs) provide a promising solution to the problem of producing large format arrays of ultra sensitive detectors for astronomy. Traditionally KIDs have been constructed from superconducting quarter-wavelength or half- wavelength resonator elements capacitively coupled to a coplanar feed line. Photons are detected by measuring the change in quasi-particle density caused by the splitting of Cooper pairs in the superconducting resonant element. This change in quasi-particle density alters the kinetic inductance, and hence the resonant frequency of the resonant element. This arrangement requires the quasi-particles generated by photon absorption to be concentrated at positions of high current density in the resonator. This is usually achieved through antenna coupling or quasi-particle trapping. For these detectors to work at wavelengths shorter than around 500 /zra where antenna coupling can introduce a significant loss of efficiency, a direct absorption method needs to be considered. One solution to this problem is the Lumped Element KID (LEKID), which shows no current variation along its length and can be arranged into a photon absorbing area coupled to free space and therefore requiring no antennas or quasi-particle trapping. The work throughout this thesis studies the properties of the LEKID device though simulation and experimental data and lays the foundation for developing an optimised detector using this direct absorption approach.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Lumped element Kinetic Inductance Detectors

Kinetic Inductance Detectors (KIDs) provide a promising solution to the problem of producing large format arrays of ultra sensitive detectors for astronomy. Traditionally KIDs have been constructed from superconducting quarter-wavelength or half- wavelength resonator elements capacitively coupled to a coplanar feed line. Photons are detected by measuring the change in quasi-particle density caused by the splitting of Cooper pairs in the superconducting resonant element. This change in quasi-particle density alters the kinetic inductance, and hence the resonant frequency of the resonant element. This arrangement requires the quasi-particles generated by photon absorption to be concentrated at positions of high current density in the resonator. This is usually achieved through antenna coupling or quasi-particle trapping. For these detectors to work at wavelengths shorter than around 500 /zra where antenna coupling can introduce a significant loss of efficiency, a direct absorption method needs to be considered. One solution to this problem is the Lumped Element KID (LEKID), which shows no current variation along its length and can be arranged into a photon absorbing area coupled to free space and therefore requiring no antennas or quasi-particle trapping. The work throughout this thesis studies the properties of the LEKID device though simulation and experimental data and lays the foundation for developing an optimised detector using this direct absorption approach

Lithographic Micro- and Nanostructuring of SU-8 for Biotechnological Applications

En aquesta tesi doctoral s’ha dut a terme recerca en mètodes de fabricació d’estructures micromètriques i nanomètriques de SU-8. La recerca ha partit de la base d’una anàlisi dels treballs anteriors en estructuració de SU-8 i ha tingut com a principal objectiu el d’obtenir noves estructures per a aplicació en biotecnologia. Un dels resultats més importants de la recerca ha estat la proposta d’una tècnica híbrida que combina fotolitografia i litografia per pressió per obtenir superfícies de SU-8 amb estructura jerarquitzada. Les investigacions també han portat a proposar un mecanisme de sensat basat en la fotoluminescència del SU-8. Els experiments demostren que la fotoluminescència es redueix a cada pas de modificació de la química de superfície. Aquesta característica es produeix de forma repetible també quan s’adhereix un antigen (IgG) a una superfície de SU-8 modificada amb l’anticòs corresponent (aIgG). Gràcies a aquest efecte, s’ha proposat un inmunosensor basat en la reducció de fotoluminescència i se n’ha avaluat la seva sensibilitat. El resultat més rellevant demostra que estructures jeràrquicament organitzades mostren una reducció de fotoluminescència major i per tant una millor sensibilitat.En esta tesis doctoral se ha llevado a cabo investigación sobre métodos de fabricación de estructuras micrométricas y nanométricas de SU-8. La investigación ha partido de la base de un análisis de los trabajos anteriores en estructuración de SU-8 y ha tenido como principal objetivo el de obtener nuevas estructuras para la aplicación en biotecnología. Uno de los resultados más relevantes de la investigación ha sido la propuesta de una técnica híbrida que combina fotolitografía con litografía por presión para obtener superficies de SU-8 con una estructura jerarquizada. Las investigaciones también han llevado a proponer un mecanismo de sentado basado en la fotoluminiscencia del SU-8. Los experimentos demuestran que la fotoluminiscencia se reduce a cada paso de modificación de la química de superficie. Esta característica se produce de forma repetible también cuando se adhiere un antigen (IgG) a una superficie de SU-8 modificada con el anticuerpo correspondiente (aIgG). Gracia a este efecto se ha propuesto un inmunosensor basado en la reducción de fotoluminiscencia i se ha evaluado su sensibilidad. El resultado más relevante demuestra que las estructuras jerárquicamente organizadas muestran una reducción de fotoluminiscencia mayor, y por tanto una mejor sensibilidadn this Ph. D. Dissertation research on lithographic methods for the fabrication of micrometric and nanometric SU-8 structures has been carried out. The research has been based on a survey of existing techniques to structure the SU-8 with the main objective of obtaining novel structures for biotechnology applications. One of the main results of the research has been the proposal of an hybrid technique that combines photolithography and soft lithography to obtain hierarchically structured SU-8 surfaces. The investigations have also led to the proposal of a sensing mechanism based on the photoluminescence of SU-8. The experiments show that photoluminescence is reduced with every step of surface chemistry modification. This is a repeatable feature that is observed also upon attachment of an antigen (IgG) onto a SU-8 surface grafted with antibody (aIgG). Thanks to this effect, an immunosensor based on the reduction of photoluminescence has been proposed and its sensitivity has been evaluated. The results show that the hierarchically patterned structures offer a higher photoluminescence reduction and thus a better sensitivity

Conception, modélisation et caractérisation de détecteurs térahertz innovants

Le but de cette thèse est d établir une modélisation électromagnétique du détecteurbolométrique térahertz (THz). Ce travail aide à faciliter la conception de bolomètre THz dontla structure est basée sur celle de bolomètre infrarouge à température ambiante. Le contextede la thèse est l imagerie THz active. Nous avons étudié le comportement électromagnétiqued un bolomètre à antenne de bande spectrale 1 5 THz. Deux modes de simulation ont étéréalisées : l une est en mode de réception et l autre est d émission. La combinaison de cesmodes de simulation constitue un outil important pour concevoir le bolomètre THz. Latechnique de spectroscopie par transformée de Fourier a été utilisée pour caractériserexpérimentalement le comportement électromagnétique du détecteur. Nous avons mesuré laréflectivité de la surface du plan focal de détecteur ainsi que la réponse spectrale du détecteur.Les deux sont confrontées avec la simulation et elles se trouvent en bon accord. Avec lesconnaissances obtenues des résultats théorique et mesuré, la recherche aide à améliorer desperformances du détecteur actuel. Nous avons aussi proposé un design pour le bolomètre defaible fréquence (850 GHz). Ce dernier ouvre la perspective d emmener la technologie debolomètre d infrarouge vers la bande sous-térahertz où l imagerie est beaucoup plusfavorable.This PhD thesis aims to establish an electromagnetic modeling of the bolometer atterahertz (THz) range that can facilitate the design of the detector from the uncooled infraredbolometer technology. The envisaged application for the detectors lies in active THz imagingat room temperature. We have studied the optical coupling of a THz antenna-coupledbolometer operating in the range 1 5 THz. Simulations in receiving and transmitting modeshave been performed to study the optical characteristics of the bolometer. The combination ofthese two simulation types leads to a powerful toolset to design terahertz bolometers. For theexperimental aspect, measurements have been performed by using Fourier-transformtechnique to study experimentally the electromagnetic behavior of the bolometer. They aremeasurement of reflectivity of the focal plane array s surface and spectral responsemeasurement. The results of measurement were found to be in good agreement with thesimulation. The understanding from the study in this PhD helps us make improvement to theactual detector. Also the design of bolometer for low frequency (850 GHz) has beenproposed. This leads to a perspective of using bolometer for terahertz imaging at thefrequency where many characteristic of the terahertz radiation are favorable for imagingapplication.SAVOIE-SCD - Bib.électronique (730659901) / SudocGRENOBLE1/INP-Bib.électronique (384210012) / SudocGRENOBLE2/3-Bib.électronique (384219901) / SudocSudocFranceF