after the previous measurement, we installed similar dampers, than the ones used belows the aluminium breadboard, placed below the 4 Menhir 160MHz "feet", in contact with the aluminium breadboard.
- in red, phase noise measurement with the Sorbothane feet below the Menhir laser and below the aluminium breadboard.
- in blue,same measurment with an additionnal heavy mass placed in the middle of the breadboard.
| Ronic Chiche wrote: |
|
comparison of the Menhir 160MHz phase noise with the CW reference.
- in blue, the oscillators are placed on top of an aluminium breadboard, placed directly on an optical table (measurement made in june)
- in red, the oscillators are placed on top of an aluminium breadboard, placed directly on top of 4 feet with Thorlabs AV4/M Sorbothane dampers, above the NeoLase amplifier (measurement made last week)
=> similar behavior with phase noise increasing around 1kHz, compared to the reference.
| Ronic Chiche wrote: |
|
measurements made with Alice:
comparison between the CW OEwaves oscillator phase noise measured last week (2 measurements done with AOM, in red and orange) with the one made in 2022 (without AOM, in blue).
one observes a degradation of the performance of the oscillator by ~10dB in the region of interest 100Hz-100kHz
| Ronic Chiche wrote: |
|
with Alice, we installed the Menhir 160MHz oscillator on a breadboad placed on top of 4 damped feet around the amplifier.
we will do an heterodyne phase noise measurement vs the CW OEwaves oscillator.
the power at the output of the Menhir oscillator is about 150mW.
after injection in the fiber (N°3 blue jacket), we got about 75mW.
we installed the 2->1 coupler to make the beating.
BE CAREFUL, the coupler is polarization sensitive, so we add a half waveplate in the Menhir path to adust the polarization on the coupler, otherwise the output power can be very low.
the coupler attenuation is ~ 3.5dB on both inputs.
the OEwaves power is ~16mW at the input and we measured ~7mW at the output of the coupler for this channel.
the Menhir fiber coupled power is ~75mW and we measured ~26mW at the output of the coupler for this channel.
|
|
|
|