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Tue Jul 2 11:21:24 2013, Erica, DailyProgress, fiber optic, mode matching        Wed Jul 3 09:46:48 2013, Erica, DailyProgress, fiber optic, mode matching           Thu Jul 11 01:40:19 2013, Erica, DailyProgress, fiber optic, mode matching              Fri Jul 12 00:51:39 2013, Erica, Notes, fiber optic, mode matching                 Tue Jul 16 10:27:47 2013, Erica, Notes, fiber optic, mode matching, beam recombination                    Tue Jul 16 11:02:47 2013, Erica, Notes, fiber optic, mode matching, beam recombination                       Wed Jul 17 11:58:47 2013, Erica, Notes, fiber optic, mode matching, beam recombination                          Wed Jul 17 18:29:37 2013, Erica, DailyProgress, fiber optic, reducing drift in the recombined beam                             Sat Jul 20 23:39:09 2013, Erica, DailyProgress, fiber optic, reducing drift in the recombined beam                                Tue Jul 23 10:29:12 2013, Erica, DailyProgress, fiber optic, reducing drift in the recombined beam                                   Tue Jul 23 11:43:00 2013, Evan, DailyProgress, Electronics Equipment, Zach's op-amp recommendations                                   Fri Jul 26 11:07:44 2013, Erica, DailyProgress, BEAT, circuit for measuring temperature fluctations on CTN table                                      Fri Jul 26 11:22:45 2013, Erica, DailyProgress, BEAT, circuit for measuring temperature fluctations on CTN table                                         Fri Jul 26 11:45:28 2013, Erica, DailyProgress, BEAT, circuit for measuring temperature fluctations on CTN table                                            Mon Jul 29 13:30:26 2013, Erica, DailyProgress, BEAT, adding resistor, capacitor, and sockets                                               Tue Jul 30 12:23:41 2013, Erica, DailyProgress, BEAT, addressed noise problem, DC signal                                                  Thu Aug 1 00:25:02 2013, Erica, DailyProgress, fiber optic, insulating foam                                                     Fri Aug 2 12:38:41 2013, tara, DailyProgress, fiber optic, insulating foam                                                        Tue Aug 6 12:31:24 2013, Erica, DailyProgress, fiber optic, insulating foam                                                           Wed Aug 7 13:27:00 2013, Erica, DailyProgress, fiber optic, more foam, calculations for convertion from voltage to frequency                                                              Wed Aug 7 18:53:20 2013, Erica, DailyProgress, fiber optic, noise budget, Matlab notes.                                                                 Tue Aug 13 12:39:36 2013, Erica, DailyProgress, fiber optic, rewrote calculations for converting from voltage noise to frequency noise                                                           Tue Aug 13 12:28:20 2013, Erica, Notes, Electronics Equipment, new AD 590 circuit and its noise calculation, beam alignment                                                              Fri Aug 16 10:35:44 2013, Erica, Notes, Electronics Equipment, AD590 msrmt, conversion to freq noise                       Tue Jul 30 16:19:32 2013, Erica, Notes, fiber optic, setup for beam recombination                       Mon Aug 5 12:21:00 2013, Erica, Notes, fiber optic, calculation: phase change for fiber        Tue Jul 30 15:48:47 2013, Erica, DailyProgress, fiber optic, noise for GYRO

Message ID: 1301     Entry time: Fri Aug 16 10:35:44 2013     In reply to: 1295 Author: Erica  Type: Notes  Category: Electronics Equipment  Subject: AD590 msrmt, conversion to freq noise

Tuesday: I added sockets to the ends of the wire to attach the AD 590 because the connection wasn't good the way were doing it before (taping it). Evan and I tested the circuit. There was some high frequency noise, which we discovered was due to the wire connecting to the AD590. We covered it with aluminum tape which helped a little, and then grounded it by connecting to the shield ground of the power supply. This also improved it but didn't remove it totally. We took spectrum data and that has been added to the Noise Budget. We realized we forgot to convert the current noise from the AD590 -(40pA/rtHz) to frequency noise. Once we did, it was higher than the free-running noise of the laser, which is reflected in the graph. The data was taken units of V^2/rtHz. To convert to frequency noise: take the sqrt divide by R4 [A/rtHz] multiply by 10^6uA/A, which gives the value in K/rtHz because the conversion for the AD590 is 1uA/K multiply by L*alpha to convert to m/rtHz multiply by c/(n^2*alpha*L*T) to convert to frequency noise. I'll write this out in Latex so it's clearer. When converting from temperature noise to length noise, we did not account for the fiber's jacket and its various materials, such as Kevlar, PVC, etc. We would solve this eqn to get the thermal time constant of the fiber. K *del^2 (T) = i*omega*T

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