  The renewed serious interest to possible practical applications of
gravitational waves is encouraging. Building on previous work, I am arguing
that the strong variable electromagnetic fields are appropriate systems for the
generation and detection of high-frequency gravitational waves (HFGW). The
advantages of electromagnetic systems are clearly seen in the proposed complete
laboratory experiment, where one has to ensure the efficiency of, both, the
process of generation and the process of detection of HFGW. Within the family
of electromagnetic systems, one still has a great variety of possible
geometrical configurations, classical and quantum states of the electromagnetic
field, detection strategies, etc. According to evaluations performed 30 years
ago, the gap between the HFGW laboratory signal and its level of detectability
is at least 4 orders of magnitude. Hopefully, new technologies of today can
remove this gap and can make the laboratory experiment feasible. The laboratory
experiment is bound to be expensive, but one should remember that a part of the
cost is likely to be reimbursed from the Nobel prize money ! Electromagnetic
systems seem also appropriate for the detection of high-frequency end of the
spectrum of relic gravitational waves. Although the current effort to observe
the stochastic background of relic gravitational waves is focused on the
opposite, very low-frequency, end of the spectrum, it would be extremely
valuable for fundamental science to detect, or put sensible upper limits on,
the high-frequency relic gravitational waves. I will briefly discuss the origin
of relic gravitational waves, the expected level of their high-frequency
signal, and the existing estimates of its detectability.

General Relativity and Quantum Cosmology;Astrophysics;High Energy Physics - Phenomenology;High Energy Physics - Theory