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ice:servo-opls [2019/11/18 23:30] – [Calculating Phase Noise] Michael Radunskyice:servo-opls [2021/08/26 15:26] (current) – external edit 127.0.0.1
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 Please read [[:limited_warranty|Limited Warranty]] and [[:warnings_cautions|General Warnings and Cautions]] prior to operating the ICE-CP1. Please read [[:limited_warranty|Limited Warranty]] and [[:warnings_cautions|General Warnings and Cautions]] prior to operating the ICE-CP1.
  
-The guide to programming the ICE-CP1 through serial commands can be [[ice:commands:opls|found here]].  The ICE-CP1 web page can be [[http://www.vescent.com/products/electronics/icetm-integrated-control-electronics/ice-cp1-current-control-and-offset-phase-lock/|found here]].+The guide to programming the ICE-CP1 through serial commands can be [[ice:commands:opls|found here]].  The ICE-CP1 web page can be [[https://vescent.com/us/d2-135-offset-phase-lock-servo.html|found here]].
  
 ===== Description ===== ===== Description =====
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 | Current range                                                                                                                                                0-200                                                                                            0-500        |  mA      | | Current range                                                                                                                                                0-200                                                                                            0-500        |  mA      |
 | Current setpoint resolution                                                                                                                                  200                                                                                              500          |  μA      | | Current setpoint resolution                                                                                                                                  200                                                                                              500          |  μA      |
-| Current noise density((All measurements guaranteed on design and verified experimentally on D2-105 which uses same circuit.))                               |  <100                                                                                            |  <200         | pA /√Hz +| Current noise density                                <100                                                                                            |  <200         | pA /√Hz 
-| RMS Noise (10Hz - 100kHz)((All measurements guaranteed on design and verified experimentally on D2-105 which uses same circuit.))                           |  <50                                                                                              <100          nA      | +| RMS Noise (10Hz - 100kHz)              |  <50                                                                                              <100          nA      | 
-| RMS Noise (10Hz - 1MHz)((All measurements guaranteed on design and verified experimentally on D2-105 which uses same circuit.))                             |  <100                                                                                            |  <150          nA      | +| RMS Noise (10Hz - 1MHz)                  |  <100                                                                                            |  <150          nA      | 
-| RMS Noise (10Hz - 10MHz)((All measurements guaranteed on design and verified experimentally on D2-105 which uses same circuit.))                            |  <300                                                                                            |  <500          nA      |+| RMS Noise (10Hz - 10MHz)                |  <300                                                                                            |  <500          nA      |
 | Absolute accuracy                                                                                                                                            2                                                                                                              ||  %       | | Absolute accuracy                                                                                                                                            2                                                                                                              ||  %       |
 ^ Offset Phase Lock Servo Input Signal                                                                                                                        ^                                                                                                                 |^          ^ ^ Offset Phase Lock Servo Input Signal                                                                                                                        ^                                                                                                                 |^          ^
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 Two numbers control the offset frequency of the ICE-CP1: The divider setting N and the reference frequency. The divider setting N can be set to N=8,16,32 or 64. The reference frequency can be generated internally with a range from 50 - 240 MHz. Or an external frequency reference can be provided (external frequency must be from 32 MHz - 240 MHz). The offset frequency of the laser is given by the following formula: Two numbers control the offset frequency of the ICE-CP1: The divider setting N and the reference frequency. The divider setting N can be set to N=8,16,32 or 64. The reference frequency can be generated internally with a range from 50 - 240 MHz. Or an external frequency reference can be provided (external frequency must be from 32 MHz - 240 MHz). The offset frequency of the laser is given by the following formula:
-<WRAP center round box 450px><html><center></html> ** Offset = N * Reference Frequency **<html></center></html></WRAP>+<WRAP center round box 260px> **Offset = N * Reference Frequency** </WRAP>
  
 The table below shows the offset range for different values of N and using the internal or external frequency reference. The table below shows the offset range for different values of N and using the internal or external frequency reference.
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-The charge pump in the OPLS outputs a signal proportional to the phase-error and the transfer function is as shown in <imgref xferfunc> However, the OPLS will typically be used to control a //frequency//-tunable device (such as a laser). In this configuration, the effective loop filter is not the one shown in <imgref opls_side_panel>, but includes a extra integration corresponding to converting the phase-error input to a frequency error. Thus, ω<sub> </sub>sets the frequency transition from single-integration to double-integration and ω<sub>I </sub> from single-integration to proportional feedback. It is important to understand this 'hidden' integrator when configuring the loop filter parameters. +The charge pump in the OPLS outputs a signal proportional to the phase-error and the transfer function is as shown in <imgref xferfunc> However, the OPLS will typically be used to control a //frequency//-tunable device (such as a laser). In this configuration, the effective loop filter is not the one shown in <imgref xferfunc>, but includes a extra integration corresponding to converting the phase-error input to a frequency error. Thus, ω<sub> </sub>sets the frequency transition from single-integration to double-integration and ω<sub>I </sub> from single-integration to proportional feedback. It is important to understand this 'hidden' integrator when configuring the loop filter parameters. 
  
 =====Calculating Phase Noise ===== =====Calculating Phase Noise =====
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 The phase-noise specified in Section 1.3 is referenced to the phase frequency detector (PFD) at 1 Hz. To convert that to the noise measured on the actual beat-note, it must be rescaled with the following formula: The phase-noise specified in Section 1.3 is referenced to the phase frequency detector (PFD) at 1 Hz. To convert that to the noise measured on the actual beat-note, it must be rescaled with the following formula:
  
-<WRAP center round box 450px> **D2-135 Phase-Noise Floor = -213 + 20Log(N) + 10Log(F<sub>REF</sub>)**</WRAP>+<WRAP center round box 450px> **D2-135 Phase-Noise Floor = -213 + 20Log(N) + 10Log(ƒ<sub>REF</sub>)**</WRAP>
  
-where N is the value of the divider and F<sub>REF</sub> is the reference frequency as measured in Hz. For more details, please see this [[http://www.vescent.com/2012/calculating-phase-noise-from-the-d2-135/|application note]].+where N is the value of the divider and ƒ<sub>REF</sub> is the reference frequency as measured in Hz. For more details, please see this [[http://www.vescent.com/2012/calculating-phase-noise-from-the-d2-135/|application note]].
  
  
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 **Beat Note Monitor ** **Beat Note Monitor **
  
-The Front Panel for the ICE-CP1 has four SMA or FC connectors. The second bottom-most connector is an SMA which is the digitized (i.e. square-wave) version of the input beat-note after a divide-by-2. For example, if the input beat note is 6 GHz, the monitor will have a 3 GHz output.  The signal is ~0 dBm in power regardless of the strength of the input beat-note signal.+The Front Panel for the ICE-CP1 has four SMA or FC connectors. The top-most connector is an SMA which is the digitized (i.e. square-wave) version of the input beat-note after a divide-by-2. For example, if the input beat note is 6 GHz, the monitor will have a 3 GHz output.  The signal is ~0 dBm in power regardless of the strength of the input beat-note signal.
  
  
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 **Beat Note Input ** **Beat Note Input **
  
-The Front Panel for the ICE-CP1 has four SMA or FC connectors. The top connector (SMA for ICE-CP1-SMA, FC for ICE-CP1-FC) is the beat note signal input. When FC, this input should be a <1 mW signal containing overlapped light from both lasers. When an SMA, this input should be an electrical signal, typically the output of the D2-160.+The Front Panel for the ICE-CP1 has four SMA or FC connectors. The SMA connector 2<sup>nd</sup> from the bottom is the beat note signal input. When FC, this input should be a <1 mW signal containing overlapped light from both lasers. When an SMA, this input should be an electrical signal, typically the output of the D2-160 or D2-260 Beat Note Detector.
  
 **Laser Current ** **Laser Current **
ice/servo-opls.1574119841.txt.gz · Last modified: 2021/08/26 14:26 (external edit)