Much thanks for your response.
While the explanation is a bit over my head it is refreshing to learn that the question I posed was an importantant one, that it had obviously been addressed by the LIGO folks and that the methods they developed are well documented in the technical literature.
Once again, thanks for your response.
My question has always been, how does the LIGO receiver take energy from the incident gravitational wave? I understand how a radio receiver matched in impedance absorbs energy from a radio wave, but how does the LIGO absorb energy? What is the equivalent of impedance matching?