Dissertation - FTP Directory Listing - University of Surrey

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As can be seen the plot exhibits some non linearity, with 2 distinct gradients appearing the first inthe range of 2000-3500 DN gives a conversion gain of K = 0.178 DN/e- and the second gradient in therange 4000-7000 DN gives a conversion gain of K = 0.105 DN/e-. There is a large discrepancybetween these figures, it is unclear what has caused this effect but it could be due to a power supplyfault resulting in the pixels being reset to an incorrect voltage.LAS was then tested in Hard reset mode with the reset voltage set to 2.5V to see if the effect wasstill present.1200temp.var - dark.temp.var [DN]10008006004002000-2000 2000 4000 6000 8000 10000 12000 14000uy - uy. darkFigure 4.20 Photon transfer curve for hard reset operationFigure 4.20 shows the photon transfer curve for LAS when operating in hard reset mode, it can beseen there is still a slight nonlinearity but far less pronounced than for soft reset. The gradient givesa conversion factor of K = 0.177 DN/e- or 1/K = 5.65 e-/DN. There appear to be no anomalous pointsacross the range.Because of the non linearity seen in soft reset further tests were performed with LAS operating inhard reset. The next plot investigates the linearity response of the sensor shown in Figure 4.21.58
10000010000uy - uy. dark [DN]1000100101100 1000 10000 100000 1000000 10000000Photons [~p]Figure 4.21 Light response of sensor for hard reset operationFigure 4.21 shows the signal output of the sensor (in digital numbers) response to increasing incidentlight intensity. The results are plotted on a log log scale so non linearity’s can be easily seen. Intheory the response should linear giving a gradient of 1 on a log log plot as the sensor responseshould be the same until full well is approached at which point the curve will level off when the pixelis full. The plot shows the expected response giving a gradient of 0.97 before levelling off to give amaximum full well of approximately 12,200 DN or 68,900 e-. This plot can also be used to calculatethe QE of the sensor which gave a QE = 19.6% at a wavelength of 546 nm.If this is compared to the linearity plot for LAS operating in soft reset it becomes clear that soft restmode is not working properly.59
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ABSTRACTThe characterisation of fou
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LIST OF ABBREVIATIONSAPSCCDCDSCMOSD
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2.8.3. FORTIS .....................
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CHAPTER 4Figure 4.1 LED uniformity
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Over the next 30 years CCDs improve
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There are 3 main types of semicondu
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2.2. Photodetectors2.2.1. The Photo
Page 16 and 17: V G < V FB V FB < V G < V T V T < V
Page 18 and 19: Figure 2.5 Cross sectional diagram
Page 20 and 21: 2.3.1.2. Interline transferIn an in
Page 22 and 23: Figure 2.9 NMOS transistor operatin
Page 24 and 25: in three main categories of CMOS se
Page 26 and 27: transistor M SEL is turned on and t
Page 28 and 29: qK = ×cA SF(2.5)Where:K = conversi
Page 30 and 31: 2.4.6. Signal to noise ratioSNR is
Page 32 and 33: When h/ ≫ this equation reduces
Page 34 and 35: The gain functions in this relation
Page 36 and 37: Where: σ (DNTOTAL) is the total no
Page 38 and 39: The Aspect system is a complete tes
Page 40 and 41: The pixel architecture (Figure 2. .
Page 42 and 43: eset, hence reducing kT/C noise. In
Page 44 and 45: Figure 2.28 Readout structure of TE
Page 46 and 47: 3.2. Sensor characterisationThe Asp
Page 48 and 49: Once everything was setup and the c
Page 50 and 51: From this it can be seen that for e
Page 52 and 53: 4.2.2. A test structure results:The
Page 54 and 55: values is 493.7 DN. The noise of te
Page 56 and 57: 20,100e-. Finally Figure 4.9 shows
Page 58 and 59: This test structure demonstrates go
Page 60 and 61: 4.2.5. D test structure results:Fig
Page 62 and 63: Of the two variants it appears D2 p
Page 64 and 65: 100Number of pixels1012000 2200 240
Page 68 and 69: 100000uy - uy. dark [DN]10000100010
Page 70 and 71: the halogen lamp had to tested with
Page 72 and 73: have an effect it is not great enou
Page 74 and 75: 10000010000uy - uy. dark [DN]100010
Page 76 and 77: temp.var - dark.temp.var [DN]500004
Page 78 and 79: effect of these changes can’t be
Page 80 and 81: 100Number of pixels1015350 5400 545
Page 82 and 83: 10000Linearityuy - uy. dark [DN]100
Page 84 and 85: lower than the standard diode. The
Page 86 and 87: 6. REFERENCES1. http://cerncourier.
Page 88 and 89: 7. APPENDICES7.1. Appendix A: EMVA
Page 90 and 91: 7.2. Appendix B: Aspect quick start
Page 92 and 93: iii)iv)Once you have followed all o
Page 94 and 95: 5. Running idVIEWi) Before running
Page 96 and 97: a) Taking Measurements with only on
Page 98 and 99: a) The EMVA Standard takes into con
Page 100 and 101: 7.3. Appendix C: Per pixel analysis
Page 102 and 103: Plot the gradient of the PTC by dra
Page 104: The final tab which both the integr
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