Midooka, Izumi,

Related log: 6239

Today, we went into the PSL clean room and actually confirmed that beatnote of the main laser and a Prometheus existed. This confirms the validity of the wavelength meter measurement reported in 6239.

• Prometheus temperature was at 21.99 deg
• Mephisto temperature was at 45.13 deg
• Beatnote was found at 40 MHz (in which the Prometheus frequency was lower than that of Mephisto).
• We have used an 818-BB-21A for the measurement.
• 26.8 mVp-p at an oscilloscope whose input impedance is 50 Ohms. This corresponds to a -27 dBm output.
• We tried to measure the incident power which seemed to be 3-ish mW. Although we are not sure how accurate this value is because the output fluctuated a lot during the measurement.