Partecipants: Marco, Eleonora , Yuhang
We match the light of the ML into the fiber.
Input power: 3mW
Matched power: 0.71*2mW
Fiber matching: 47%
After that we control the matching of the AUX2 fiber:
Input power: 3.5mW
Matched power: 1.25*2mW
Fiber matching: 71%
Voltage level on photodiode:
ML: 7.8V
AUX1: 5.2V
Total: 2.6V
We found the beat note between the two lasers and we measure the following levels:
| Beat note | Amplified signal | 90% signal | 10 % signal | |
| Carrier | -21dBm | -6.33dBm | -7.67 dBm | -17.60 dBm |
| Sideband 1° order | -33.8dBm | -17.67dBm | -18.33dBm | -29.43 dBm |
| Sideband 2° order | -54dBm | -38.17dBm | -38.67dBm | -49.77 dBm |
| Sideband 3° order | not visible | -65.33dBm | -61.50dBm | not visible |
The AUX1 laser temperature was set at 30.67 °C, at the spectrum analyzer we see both the beat note and the lateral sidebands due to EOM modulation.
The minimum level required for the beat note to lock the PLL is -16 dBm, thus the amplitude of the carrier is enough to perform the PLL locking. Concerning the sideband to perform the lock on them their level must be incresed at least of 2-3 dBm
