Hello! I am building a bow-tie cavity and for some reason the peaks I see when scanning the laser frequency are extremely wide and with a very long tail to the right. However, if I put a 50 Ohm resistance in between the BNC cable from the diode and the oscilloscope (using a BNC T connector) the peaks become narrow (as narrow as I would expect from the calculations) and the tail is significantly reduced (although not gone completely). Why is this happening? I expected that adding the 50 Ohm would reduce the amplitude (which happens, too), but why the linewidth? The issue is that now the amplitude is so much reduced that it is too small to send it to the servo, and if I don't use the 50 Ohm I have the original problem. Any advice would be appreciated. Thank you!