a spectral resolution of
by a sinusoidal spectrum (with period provided by an
optical filter. If is small enough, the overall effect
is similar to a sampling by a train of delta functions with the difference
that the sampling signal does not reach the zero value.
This results in a semi-discrete time filter which eliminates spectral
periodicity so only two resonances (one at baseband which
can be blocked) and another at the frequency of interest are generated.
The resonance position is controlled by the spectral period
of the sinusoidal sampler , while the peak to SSL ratio
is given by . The left part of Fig. 9 shows a layout of
this structure and illustrates the basic operating principle while
the right part provides experimental versus theoretical results
obtained when a squared and a Gaussian source