EX PLL measurements

(Alexa, Daniel, Sheila)

PLL Beatnote:

• Beatnote height of -11.6dBm (or -24dBm before the preamplifier which has a gain of 12dB)
• BBPD reads 5.2mW
• Input 1 pol: NEG, Common Compensation: ON, Generic Filter: ON, Fast Option: ON, Fast Gain: -8dB, rest OFF ---- under this configuration we found the lock was unstable with the input 1 gain at 6dB
• Turning Boost 1: ON, the lock was then unstable with the input 1 gain at 4dB
• We decided the best stable configuration was with the input 1 gain set to 0dB (gives a factor of 2 gain margin)

PLL Open Loop Transfer Function:

• Input 1 pol: NEG, Common Compensation: ON, Generic Filter: ON, Fast Option: ON, Fast Gain: -8dB, Input 1 Gain: 0db, rest OFF
  • EX_PLL_OpenLoopTFmag_BoostOff EX_PLL_OpenLoopTFphase_BoostOff  (collected with SR785)
  • EX_PLL_OpenLoopTF_High_BoostOff/AAAA2.TXT (collected with RF spectrum analyzer for high freq)
  • UGF at 22kHz, phase margin of 50 deg
• Input 1 pol: NEG, Common Compensation: ON, Generic Filter: ON, Fast Option: ON, Fast Gain: -8dB, Input 1 Gain: 0db, Boost 1: ON rest OFF
  •  EX_PLL_OpenLoopTFphase_BoostOn (collected with SR785, need to recollect mag data)
  • EX_PLL_OpenLoopTF_High_BoostOn/AAAA3.TXT (collected with RF spectrum analyzer for high freq)
  • UGF at 26kHz, phase margin of 20 deg

PLL Noise Spectrum -- via IMON of PFD (S1000758)

• PFD test report indicates the board has a noise of ~500nV/SqrtHz from IMON
• Input 1 pol: NEG, Common Compensation: ON, Generic Filter: ON, Fast Option: ON, Fast Gain: -8dB, Input 1 Gain: 0db, rest OFF
  • EX_PLL_Noise_PFD_BoostOff (collected with SR785)
  • EX_PLL_Noise_PFD_High_BoostOff/AAAA4.TXT (collected with RF spectrum analyzer for high freq)
• Input 1 pol: NEG, Common Compensation: ON, Generic Filter: ON, Fast Option: ON, Fast Gain: -8dB, Input 1 Gain: 0db, Boost 1: ON, rest OFF
  • EX_PLL_Noise_PFD_BoostOn (collected with SR785)

PLL Servo Board Transfer Function:

 

• Input 1 pol: NEG, Common Compensation: ON, Generic Filter: ON, Fast Option: ON, Fast Gain: -8dB, Input 1 Gain: 0db, rest OFF
  • EX_PLL_ServoBoard_TFmag_BoostOff, EX_PLL_ServoBoard_TFphase_BoostOff (collected with SR785)
• Input 1 pol: NEG, Common Compensation: ON, Generic Filter: ON, Fast Option: ON, Fast Gain: -8dB, Input 1 Gain: 0db, Boost 1: ON, rest OFF
  • EX_PLL_ServoBoard_TFmag_BoostOn, EX_PLL_ServoBoard_TFphase_BoostOn (collected with SR785)
• Note: DC gain of -30dB nominal

Shot Noise of PLL BBPD:

• Measured noise from laser to be -95dB at 100Hz BW
• Noise of RF spectrum was -100dBm at 10Hz BW