====== Three Corner Hat Measurement ======

===== First measurement ideas =====
=== Jan´s laser vs. Comb Hannover ===
{{:groups:mg:img_1311.jpg?300 |}}  
  * purple = current setup (06.10.2016)
  * blue = setup for measurement
  * red = unstabilized fiber -> keep it short!

=== Jan´s laser vs. Comb Hannover and Link vs. Comb Hannover ===
{{:groups:mg:img_1312.jpg?300 |}}
  * Shift the ManyPointBox and Link to the optical table


===== Second Try =====

{{:groups:mg:dsc07611.jpg?300|}}


===== Final Setup =====
==== Optical part ====

{{:groups:mg:dsc07613.jpg?300|}}

==== Electronic part ====
{{ :groups:mg:virtuel_beat_-_three_corner_head_measurement.pdf |Three Corner Hat Measurement - PDF-version}}\\
{{:groups:mg:virtuel_beat_-_three_corner_head_measurement.jpg?800|}}





===== 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 ====
Ratio: N=n916/nLink = 3275292/1944000 = 1.684820987654321...\\
Inverted Ration: N'=1/N\\
For DDRS: M=(N')*2^48 = 167065212727755.34375 (dez) = 97f1e6a8b1cb.58 (hex) ~= **97f1e6a8b1cb** (hex)\\


Alte Berechnung (Es wurden die Frequenzen geteilt und nicht die Modennummern)
      - -> ratio of ~ 1,684807 
      - -> 474231011086950,203392
      - [Hex]: 1AF4F82F51266
      - -> Inverted Ratio: 0,5935397770762964267907798116259  
      - 0,5935397770762964267907798116259 * 2^48 = 167066594929398,49071775301797611
      - 167066594929398 [Deg] entspricht 97F2390B6AF6 [Hex]

-> Type 97F2390B6AF6 into the divider!!!