Cao, Dan

One of the useful features of a phase camera is its ability to selectively image different frequency components in an optical field. So today we worked  on getting the phase camera hardware+software imaging  the carrier, 9, and 45 MHz sidebands. Attached are single shots of each as an example of what the phase camera can output.

From the 9 and 45 images we have a clean round wavefront and both are looking reasonably gaussian in amplitude, as they are both resonant in DRMI. The carrier however is anti-resonant so there's worse SNR and the beam is not as clean. Averaging over 30 shots we can bring out some more detail and we can clearly see the beam has some higher order mode content relative to the sidebands. You'll notice in the 9 and 45 images that there are some broad vertical line features, this is an artifact of the rolling shutter on the Andor Zyla camera we are using and they typically average out over multiple frames. The cause is from changes in amplitude or phase in the IFO or reference beams which vary as each column on CMOS sensor is read out.