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Virtual Beat Measurement

Theory

Equations for comb:

  • For Total Virtual Beat double f_CEO
  • Compare to Postprocessing Virtual Beat Measurement!
  • You find a program, Virtual Beat, to simulate the virtuel beat under: \\afs\iqo.uni-hannover.de\projects\magnesium\Mathematica\Kamm

Scheme from:Kerr-lens mode-locked lasers as transfer oscillators for optical frequency measurements, H. R. Telle et al., arXiv:physics/0107037v1 [physics.optics] (2001)

Frequencies

  • Jan's Laser = 194.401.549 MHz (fine with Protocolbook 194.401.556 MHz).
  • 916nm clock laser: 327.5291 THz (accuracy maybe worse than 100 MHz)

Measured with wavemeter in PTB (accuracy: +-30 MHz):

  • 194.400.001 MHz Laser
  • -47 MHz Regel-AOM
  • +36 MHz Manypoint-extraktion-AOM

→ 194.399.990 MHz

Jan's transportable laser has a higher frequency:

  • Mixer in Hannover run with +1515 MHz
  • Beat is +44 MHz
  • Jan's Laser = 194.401.549 MHz (fine with Protocolbook 194.401.556 MHz)

DDS-Programming

  1. → ratio of ~ 1,684807
  2. → 474231011086950,203392
  3. [Hex]: 1AF4F82F51266
  4. → Inverted Ratio: 0,5935397770762964267907798116259
  5. 0,5935397770762964267907798116259 * 2^48 = 167066594929398,49071775301797611
  6. 167066594929398 [Deg] entspricht 97F2390B6AF6 [Hex]

→ Type 97F2390B6AF6 into the divider!!!

First measurement ideas

Jan´s laser vs. Comb Hannover

  • purple = current setup (06.10.2016)
  • blue = setup for measurement
  • red = unstabilized fiber → keep it short!

  • Shift the ManyPointBox and Link to the optical table

Second Try

Final Setup