2. Detection Methods Coherent ↔ Incoherent Photon Detection ↔ Bolometric Photon Counting ↔ Integrating

3. Radio Telescopes Typical Designs Heterodyne Receivers

4. Jansky’s First Radio Telescope 1933

5. Grote Reber: 1937 Radio Telescope

10. Heterodyne Receivers Mix signal and local oscillator Mixed signal contains “intermediate frequency” f_signal – f_local but also the sum of the frequencies

11. Heterodyne Signal Detection

15. MM and Sub-MM Telescopes Use both coherent and incoherent detection Heterodyne receivers for emission-lines Mostly bolometers for continuum

16. Millimeter Valley on Mauna Kea

18. NGC 6334

20. Detection Methods Coherent ↔ Incoherent Photon Detection ↔ Bolometric Photon Counting ↔ Integrating

21. Bolometers Absorb and thermalize photons Measure temperature change Balance between heating and cooling results in long time constants Typically used in chopped operation

28. Transition Edge Sensors: Extreme sensitivity to small temperature changes allows to build very sensitive bolometer arrays

30. Photocathods The photoelectric effect Quantum nature of light Photomultipliers, channel plates …

31. Detection Methods Coherent ↔ Incoherent Photon Detection ↔ Bolometric Photon Counting ↔ Integrating

38. Photocathod Devices Cathods Photomultiplier Image intensifiers Microchannel plates

39. In 1907 Joel Stebbins pioneered the use of photoelectric devices in Astronomy

40. Photomultiplier tubes: pile up errors Each detected photon produces a pulse of finite duration, t 0, which causes a dead time in the detector. The number of pulses (exposure time) is reduced by the amount of overlapping deadtimes. N = n/(1–t 0 n) N is the true rate, and n the apparent rate Pile-up errors System blocks completely at high light levels

42. 1840 J.W. Draper makes a photograph of the moon. Followed by photographs of the Sun by Foucault and Fizeau Sunspots photographed in 1858 by W. De La Rue Jansen and Lockyer in the 1870s photographed the solar spectrum and discovered the spectral lines of Helium. Ainsee Common photographed Orion Nebula and these revealed stars and details you could not see in a telescope Photographs by Hubble in the early 1900‘s established that some nebula where „island universes“ (i.e. galaxies). His spectral observations of galaxies (exposures of more than one night) led to the discovery of the expansion of the Universe. For 100 years photographic plates/film dominated the field of astronomical detectors. A Revolution in Detectors: Photographic Plates

43. Detection Methods Coherent ↔ Incoherent Photon Detection ↔ Bolometric Photon Counting ↔ Integrating

44. Physics of Semiconductors Basic Quantum Physics Solids Semiconductors PN Junctions

52. Semiconductors Conduction in semiconductors Doping

53. Detection Methods Coherent ↔ Incoherent Photon Detection ↔ Bolometric Photon Counting ↔ Integrating

62. PN Junctions Formation of pn junction Rectifying properties Charge separating properties

71. Electronics PN junctions and photodiodes Field Effect transistors Logic devices Analog switches Operational amplifiers A practical example

72. Field Effect Transistor Junction FET (JFET) Metal-Oxide-Semiconductor FET (MOSFET) CMOS circuits (Complementary Oxide Semiconductor)

82. Fabrication of Integrated Circuits Doping Depositing metal Growing oxides (as isolators) All controlled by photoresist masking

83. HAWAII-2: Photolithographically Abut 4 CMOS Reticles to Produce Each 2048 2 ROIC Twelve 2048 2 ROICs per 8” Wafer 2048 2 Readout Provides Low Read Noise for Visible and MWIR

84. 3-D Barrier to Prevent Glow from Reaching the Detector