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groups:mg:virtual_beat [2017/03/29 07:34] – [DDS-Programming] klausgroups:mg:virtual_beat [2018/09/04 13:01] (current) – removed ssauer
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-====== Virtual Beat Measurement ====== 
- 
-=====Scheme=====  
-{{ :groups:mg:paper_virtual_beat.pdf |Kerr-lens mode-locked lasers as transfer oscillators for optical frequency measurements}}, H. R. Telle et al., arXiv:physics/0107037v1 [physics.optics] (2001) 
- 
-{{:groups:mg:virtual_beat.jpg?400|}} 
- 
-===== Theory ===== 
- 
-Equations for comb:\\ 
-{{:groups:mg:dsc07612.jpg?500|}} 
-  * 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  
- 
- 
- 
-===== 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 
-//Alte Berechnung 
-      - -> 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!!! 
- 
-[[Three_corner_head_measurement|Three corner head measurement]]