The size of TEM01 compared to TEM00 is much worse than before. 01 mode used to be just 30% of 00 mode back in September 5th. Now it's 70%. 

Note that no alignment in air could've caused this. We suspect that the fiber is slowly degrading and slowly spitting out higher order modes.

Here's data from today (top) comparing to data taken on Sep 5 (bottom). Both cavity scan was without the 20dB attenuator on at 80MHz (hence the clearly visible sideband peaks).

The end.