fiber fig9 shows an example of an osr formed by a non gaussian shaped band pass filter fig9 shows the transmission profile in db scale as well as the derivative or frequency dependent slope of the osr fig9 also shows the spectral position of the input fm signal to be reshaped it is a preferred embodiment of the present invention that the optimal spectral position of the fm signal on the osr be such that the is peak frequency be near the peak logarithmic derivative of the transmission profile of the osr in this example the derivative is not linear on the db scale indicating that the osr has a non gaussian spectral profile a gaussian osr would have a linear slope as a function of frequency fig9 also shows the position of the clock frequency components of the input fm signal which are reduced substantially after the osr this in turn reduces the clock frequency components in the rf spectrum of the resulting second signal after the osr in this example the peak slope is 2 7 db ghz and the 3 db bandwidth of the osr in this case is approximately 8 ghz it is an embodiment of the present invention for the osr to also reduce the clock.