## page was renamed from Electronics/POX
The data for the following measurements is located at [[https://nodus.ligo.caltech.edu:30889/svn/trunk/docs/upgrade08/RFsystem/RFphotodiodes/POX/|/svn/trunk/docs/upgrade08/RFsystem/RFphotodiodes/POX/]]

[[attachment:POX_modified_schematic.png|Schematic]]

== RF Transimpedance ==

{{attachment:transimpedance.png}}

The above fit was done in LISO in root mode. The results of the fit are the following:

factor = (-2.1 +- 0.2) Ohms

delay = (9.57 +- 0.02) ns

five poles:
|| frequency (MHz) || Q ||
|| 11.133 +- 0.003 || 14.3 +- 0.1 ||
|| 11.45 +- 0.06 || 0.595 +- 0.005 ||
|| 25.46 +- 0.02 || 5.89 +- 0.07 ||
|| 224.33 +-0.02 || 124 +- 4 ||
|| 100.7 +- 0.9 || 706.82 +- 0.04 ||

four zeros:
|| frequency (MHz) || Q ||
|| 22.67 +- 0.01 || 35 +- 1 ||
|| 55.4 +- 0.3 || (10.0 +- 0.2) x 10^6^ ||
|| 0.93 +- 0.04 || 3.9 +- 0.6 ||
|| 143 +- 3 || 631.94 +- 0.04 ||

chi^2/ndf = 432

=== Alberto's LISO Model ===

[[attachment:pox_tf.pdf]]

=== Fits To Resonance ===

More detailed transfer functions were measured around the resonance peaks at 11, 22, and 55 MHz. These transfer functions were fit to {{attachment:resfitfunc.png}} where ''f'',,0,, is the resonant frequency and ''Gamma'' is the line width. ''Q'' is calculated by ''f'',,0,,/''Gamma''.

==== 11 MHz Resonance ====

{{attachment:res1.png}}

''f'',,0,, = (11.14 +- 0.01) MHz

''Gamma'' = (764 +- 1) kHz

''R'',,0,, = (8.38 +- 0.01) x 10^8^ Hz Ohms

''C'' = (11.14 +- 0.05) Ohms

chi^2/ndf = 95.4

==== 22 MHz Resonance ====

{{attachment:res2.png}}

''f'',,0,, = (22.68 +- 0.01) MHz

''Gamma'' = (820 +- 1) kHz

''R'',,0,, = (-5.64 +- 0.01) x 10^6^ Hz Ohms

''C'' = (23.44 +- 0.01) Ohms

chi^2/ndf = 12.7

==== 55 MHz Resonance ====

{{attachment:res3.png}}

''f'',,0,, = (55.29 +- 0.01) MHz

''Gamma'' = (1.74 +- 0.01) MHz

''R'',,0,, = (-9.98 +- 0.01) x 10^5^ Hz Ohms

''C'' = (1.62 +- 0.01) Ohms

chi^2/ndf = 3.22

== Noise ==

{{attachment:noise.png}}

The noise data was fit to {{attachment:fitfunc.png}} with the following results:

''Z'',,RF,, = (2.07 +- 0.01) kOhms

''I'',,d,, = (247 +- 6) uA

chi^2^ / ndf = 42

Note that this value for the transimpedance agrees with the above transfer functions since the noise was measured at 11 MHz instead of the resonance frequency of 11.14 MHz.

=== Alberto's LISO Model ===

[[attachment:pox_noise.pdf]]

== RF Behavior with No Light ==

{{attachment:timeseries.png}}

{{attachment:dark_spectrum.png}}

== Picture of Photodiode ==

{{attachment:POX.jpg}}

Picture taken on 12/13/2010.