Not sure if this is the correct forum for this, but it is calibration related.
Lets say I have a laser source with a PMF adapter fitted. And I use a normal singlemode fiber to measure the output power and wavelength.
Apart from the obvious polarisation issues, is it going to cause a problem interfacing a normal singlemode fiber, to a PMF adapter ? I mean, would the mismatch cause me to read a low power level ?