Differences between revisions 3 and 17 (spanning 14 versions)

PRMI Noise budget

Noise curves to be included
- Shot noise
- DAC noise
- Alignment noise
- Up conversion noise
- what else ?

Measurements

7/Mar/2012 by KI

Sensor in use

AS55_Q for MIHC
- Gain of whitening filter = 30 dB
- Demodulation phase = 17.6 deg
REFL33_I for PRCL
- Gain of whitening filter = 42 dB
- Demodulation phase = -38.050 deg

LO = 11065910 Hz by a Marconi

DC light

port name	DC power [mW]
AS (before the attenuation)	0.02 mW
AS55	? mW
REFL (before the attenuation)	644 mW
REFL11	? mW
REFL33	? mW
REFL55	? mW
REFL165	? mW

Sidebands

The values noted here were estimated from the OSAs at the AS and REFL ports.

Optical gains

MICH sensor parameters
description	values	notes
Estimated Optical gain	uW/m
Measured pk-pk Michelson error signal	1000 counts	Michelson was freely swinging
Raw optical gain	Hm = 1.034768e+11 [counts/m]	= 4 * pi / lambda * (pk value of the error signal)
Conversion loss of mixer	6.5 dB	from the spec sheet of JMS-1H
ADC conversion	1638.4 counts / V	16 bit, +/-20 V
Trans impedance at 55 MHz	556.3 Ohm	AS55 characterization
Responsibity of diodes	0.8 [A/W]	from the spec sheet of CS3102
Attenuation in the AS path

PRCL sensor parameters
description	values	notes
Estimated Optical gain
Measured pk-pk Michelson error signal	1000 counts	Michelson was freely swinging
Raw optical gain	Hp = 5.934718e+10 [counts/m]	= 4 * pi / lambda * (pk value of the error signal)
Conversion loss of mixer	6.5 dB	from the spec sheet of JMS-1H
ADC conversion	1638.4 counts / V	16 bit, +/-20 V
Trans impedance at 55 MHz	556.3 Ohm	AS55 characterization
Responsibity of diodes	0.8 [A/W]	from the spec sheet of CS3102
Attenuation in the AS path

Servo filters

MICH servo
description	values	notes
UGF	100 Hz
Filters activated	FM5(10:1000)
Gain	G = -5
Feedback	-0.9905 * ITMX + 1 * ITMY	via the output matrix
Dewhitening filter	On	in both ITMX and ITMY
Limiter	off
Time delay	480 usec	without considering the effects from analog circuits and downsampling filters

PRCL servo
description	values	notes
UGF	100 Hz
Filters activated	FM5(10:1000)
Gain	G = - 0.04
Power Normalization	REFL33/POYDC/0.25	via the normalization matrix
Feedback	PRM
Dewhitening filter	On	PRM
Limiter	off
Time delay	480 usec	without considering the effects from analog circuits and downsampling filters

Note: the following values are assumed for fitting the data

     ITMX  = 4.913e-09 / f2   [m/counts]
     ITMY  = 4.832e-09 / f2   [m/counts]
     PRM   = 2.022e-08 / f2  [m/counts]

For more details see summary of the actuators

RAM effects

Is something going on ?

Interferometer_Characterization/PRMI_Noise_Budget (last edited 2012-03-08 23:13:09 by KiwamuizumiATligoDOTorg)

-  ⇤ ← Revision 3 as of 2012-03-08 09:27:59 → 
  Size: 2084
  Editor: KiwamuizumiATligoDOTorg
  Comment:
+   ← Revision 17 as of 2012-03-08 23:13:09 → ⇥
  Size: 3911
  Editor: KiwamuizumiATligoDOTorg
  Comment:
-Deletions are marked like this.
+Additions are marked like this.
 Line 3:
+{{attachment:MICHbudget.png}}

{{attachment:PRCLbudget.png}}


<<BR>>
<<BR>>
  * Noise curves to be included
     * Shot noise
     * DAC noise
     * Alignment noise
     * Up conversion noise
     * what else ?
-Line 5:
+Line 18:
-{{attachment:PRMIbudgettotal.png}}
-Line 11:
+Line 23:
-   * ''' Gain of whitening filter = 30 dB ''' for both the I and Q.
   * ''' Demodulation phase = 5.4 deg ''' (at which the I signal doesn't respond to the Michelson displacement).
   * ~ very tiny DC light is on the RFPD
+   * ''' Gain of whitening filter = 30 dB '''
   * ''' Demodulation phase = 17.6 deg '''
 <<BR>>
-Line 15:
+Line 27:
-   * ''' Gain of whitening filter = 42 dB ''' for both the I and Q.
   * clear
+   * ''' Gain of whitening filter = 42 dB '''
   * ''' Demodulation phase = -38.050 deg ''' 

<<BR>>
  * ''' LO = 11065910 Hz ''' by a Marconi
-Line 20:
+Line 35:
- || AS55 || 0.02 mW ||
 || REFL ||  644 mW  ||
+ || AS (before the attenuation)|| 0.02 mW ||
 || AS55 || ? mW ||
 || REFL (before the attenuation)||  644 mW  ||
 || REFL11 || ? mW ||
 || REFL33 || ? mW ||
 || REFL55 || ? mW ||
 || REFL165 || ? mW ||
-Line 29:
+Line 49:
-  ||<-3> ''''' Parameters ''''' ||
+  ||<-3> ''''' MICH sensor parameters ''''' ||
-Line 31:
+Line 51:
-  || Estimated Optical gain || 80 uW/m || ||
+  || Estimated Optical gain ||  uW/m || ||
-Line 33:
+Line 53:
-  || Raw optical gain ||  5.9052 x10^9 [counts/meter] || = 4 * pi / lambda * (pk value of the error signal)||
+  || Raw optical gain ||  Hm = 1.034768e+11 [counts/m] || = 4 * pi / lambda * (pk value of the error signal)||
  || Conversion loss of mixer ||  6.5 dB  ||from the spec sheet of JMS-1H  ||
  || ADC conversion ||  1638.4 counts / V || 16 bit, +/-20 V  ||
  || Trans impedance at 55 MHz || 556.3 Ohm || [[Electronics/RFPD/AS55| AS55 characterization ]] ||
  || Responsibity of diodes ||  0.8 [A/W] || from the spec sheet of CS3102 ||
  || Attenuation in the AS path  || || ||

<<BR>>
<<BR>>
  ||<-3> ''''' PRCL sensor parameters ''''' ||
  || ''' description ''' || ''' values ''' || ''' notes '''||
  || Estimated Optical gain ||   || ||
  || Measured pk-pk Michelson error signal || 1000 counts || Michelson was freely swinging||
  || Raw optical gain ||  Hp = 5.934718e+10 [counts/m] || = 4 * pi / lambda * (pk value of the error signal)||
-Line 41:
+Line 74:
-Line 42:
+Line 76:
- * UGF = 55 Hz
 * Only FM5 (10:1000) was activated.
 * G = -2 
 * No limiter in the digital path.
 * Feeding the signal back to BS.
 * Dewhitening filters in BS are ON.
 * Assumption : BS actuator has a pole at 1 Hz with Q = 5
 * Time delay = (without considering the effects from the analog circuits and the down sampleing filters.)
+ {{attachment:oltf_prmi.png }}
-Line 51:
+Line 78:
+ ||<-4> ''''' MICH servo '''''||
 || ''' description '''|| ''' values ''' || ''' notes ''' ||
 || UGF || 100 Hz || ||
 || Filters activated || FM5(10:1000) ||  ||
 || Gain || G = -5  ||  ||
 || Feedback || -0.9905 * ITMX + 1 * ITMY || via the output matrix||
 || Dewhitening filter || On || in both ITMX and ITMY ||
 || Limiter ||  off || ||
 || Time delay || 480 usec || without considering the effects from analog circuits and downsampling filters ||
 
 <<BR>>
 <<BR>>
 ||<-4> ''''' PRCL servo '''''||
 || ''' description '''|| ''' values ''' || ''' notes ''' ||
 || UGF || 100 Hz || ||
 || Filters activated || FM5(10:1000) ||  ||
 || Gain || G = - 0.04  ||  ||
 || Power Normalization || REFL33/POYDC/0.25 || via the normalization matrix ||
 || Feedback || PRM || ||
 || Dewhitening filter || On || PRM ||
 || Limiter ||  off || ||
 || Time delay || 480 usec || without considering the effects from analog circuits and downsampling filters ||
 
 
 
<<BR>>
 . Note: the following values are assumed for fitting the data
 . {{{
     ITMX  = 4.913e-09 / f2   [m/counts]
     ITMY  = 4.832e-09 / f2   [m/counts]
     PRM   = 2.022e-08 / f2  [m/counts]
}}}

 . For more details see [[Interferometer_Characterization#Calibration_of_Actuator_responses| summary of the actuators]]
-Line 53:
+Line 114:
- * There is a big RAM signal in the I signal. The signals float from -100 counts to 0 counts as the Michelson freely swings.
   * The amount of the RAM looks changing as a function of time. 
 * The Q signal looks having not so much RAM effect.
+ * Is something going on ?