Differences between revisions 52 and 53
⇤ ← Revision 52 as of 2011-04-29 05:32:28 →
Size: 3730
Editor: AidanBrooks
Comment:
← Revision 53 as of 2011-04-29 05:34:30 → ⇥
Size: 3736
Editor: AidanBrooks
Comment:
Deletions are marked like this. Additions are marked like this.
Line 149: Line 149:
-----

Overview of green electronics

  • Preliminary design for the electronics used in 40m green locking.

electronics_diagram.png

Contents

  1. Overview of green electronics
  2. VCO for frequency tracking
    1. VCO range
    2. Filter respons
    3. Noise performance
    4. Capture range and Lock range
    5. lock detection and boost
  3. PDH box
    1. Filter Shape
    2. Noise performance
    3. LPF for RF cutoff
    4. Remotely controlled Boost switch
  4. frequency counter
  5. digital channel assign
  6. wideband RFPD for green PLL
    1. frequency response
    2. noise performance
  7. DC PDs
    1. PDA36A
  8. digital front end filters
  9. Thermal feedback LPF
    1. circuit diagram
    2. expected transfer function of compound frequency actuator
  10. Function Generator
  11. Summing Amplifier
    1. Diagram
    2. noise performance
  12. Temperature Controller for doubling oves
  13. RF stuff
    1. low noise amplifier
    2. mid power amplifier
    3. power splitter
    4. DC block
    5. Low frequency mixer
  14. Power Supply and Cables
    1. HV cables (-150V) for photodiode bias
    2. 15V and 24V lines
  15. RS232 serial device server
  16. Vertex BeatBox

BRBR

VCO for frequency tracking

VCO range

  • Synergy VCO part number XXX has 1.2MHz/V VCO range.

attachment:VCO_range.png

Filter respons

  • 80MHz LIGO VCO box is used to readout the frequency of the beat signal precisely.

attachment:VCO_filter.png

Noise performance

Capture range and Lock range

  • According to a simple calculations...

lock detection and boost

  • rms detection

BR

PDH box

Filter Shape

attachment:TF_PDH.png

Noise performance

LPF for RF cutoff

Remotely controlled Boost switch

BR

frequency counter

  • SR620 is employed to read out the frequency of the beat signal.

attachment:SR620.png

setting parameters

readout range

MHz

DAC bit resolution

noise

BR

digital channel assign

green_digital.pngBR

wideband RFPD for green PLL

  • A Silicon photodiode with the diameter of 10mm is used. To have a fast response up to about 1MHz -150V is applied onto the photo diode.

The schematic is available on [https://nodus.ligo.caltech.edu:30889/svn/trunk/alberto/40mUpgrade/RFsystem/RFPDs/GreenLockingBroadBandPD svn]

Hartmut_RFPD.jpg

  • EG&G SGD-444A Si PIN PD attachment:SGD-444A.pdf

frequency response

attachment:RFPD_tf.png

noise performance

attachment:RFPDnoise.png

Here is the noise model for the RFPD using liso. attachment:liso_RFPD.png

BR

DC PDs

PDA36A

  • attachment:PDA36A.png

parameters

trans impedance gain

[V/A]

responsibility

[A/W]

quantum efficiency

[%]

output impedance

50

[Ohm]

BR

digital front end filters

  • anti-aliasing filter
  • anti-imaging filter
  • whitening filter

BR

Thermal feedback LPF

circuit diagram

attachment:thermalLPF.png

expected transfer function of compound frequency actuator

attachment:thermal_actuator.png

BR

Function Generator

  • To get a phase modulation imposed on the end IR lasers, a function generator is needed.

SR___

BR

Summing Amplifier

In order to send a feedback signal and modulation signal to the laser PZT at the same time, it is desired to have a summing amplifier. The amplifier should handle the signal from DC to 200kHz. Currently this is taken place by SR560.

Diagram

noise performance

BR

Temperature Controller for doubling oves

  • TC200 from Thorlabs

  • attachment:tc200.jpg

BR

RF stuff

low noise amplifier

  • ZFL-1000 from mini circuit or similar families

  • attachment:zfl1000.png

mid power amplifier

power splitter

  • ZFRSC-42 from mini circuit. DC-4.2GHz

  • attachment:k18.jpg

DC block

  • BLK-89 from mini circuit. 50 Ohm, 100kHz-8GHz

  • attachment:ff888.jpg

Low frequency mixer

  • ZAD-8 from mini circuit. 500Hz-10MHz.

  • attachment:m22.jpg

BR

Power Supply and Cables

HV cables (-150V) for photodiode bias

15V and 24V lines

BR

RS232 serial device server

Vertex BeatBox

  • attachment:vertex_green_beatbox.pdf
  • attachment:vertex_green_beatnox.graffle

Advanced_Techniques/Green_Locking/Electronics (last edited 2017-04-20 01:58:36 by RanaadhikariATligoDOTorg)