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This Defense Intelligence Reference Document was prepared by the Defense Intelligence Agency under its Advanced Aerospace Weapon System Applications (AAWSA) program, is dated 6 April 2010 and is part of a series of advanced technology reports produced in FY 2009. It reviews proposed laboratory generators and detectors of high-frequency gravitational waves for communications. It favors an infrared-excited molecules transmitter and the Li-Baker detector, estimating about 1.9 million bits per second over 7,000 km through the Earth. It also discusses timing standards and interplanetary navigation uses.
UNCLASSIFIED//F'iA. 'iFFilil,t,I, l!l!ii! 8111!1f same frequency, direction and phase. This situation is termed "synchro-resonance." These PPF detection photons a are generated as the EM wave propagates along its z- axis path, which is also the path of the GWs, as shown in Figure 12. The magnetic field is in they-direction. According to the Li-Effect, the PPF detection photon flux (also called the "Poynting Vector") moves out along the x-axis in both directions. The signal (the PPF) and the noise, or background photon flux (BPF) from the Gaussian beam have very different physical behaviors. The BPF (background noise photons) are from the synchro-resonant EM Gaussian beam and move in the z-direction, whereas the PPF (signal photons) move out in the x-direction along the x-axis. The PPF signal can be intercepted by electromagnetic-interference-shielded microwave receivers located on the x-axis (isolated from the synchro-resonance Gaussian EM field, which is along the z-axis). In addition, isolation is further improved by cooling the microwave receiver apparatus to greatly reduce thermal noise background (Baker, Stephenson and Li, 2008a). The resultant efficiency of detection of HFGWs is very much greater than from the inverse Gertsenshtein effect, which has been exploited in some previously proposed HFGW detectors and found to have insufficient sensitivity to HFGWs (Eardley, et al., 2008). The amplitude of the PPF has space accumulation dependence-that is, it is proportional to the length of the wave overlap. This is because the GWs (gravitons) and EM waves (photons) have identical propagation velocities, so that the two waves overlap synchronously and coherently throughout and their interaction is cumulative (Boccaletti et al., 1970; Delogi and Mickelson, 1977). This is the synchro-resonant condition or Li-effect. This means that for maximum signal, the interaction overlap coupling must be as long as possible. It should be noted that the identification of this coupling or Li-effect, upon which the Li-Baker HFGW detector is based, is not so new that it is untested in the literature. At least nine peer-reviewed research publications concerning the theory have appeared following Li, Tang and Zhao (1992), including those by Li and Tang (1997), Li eta/. (2000), Li, Tang and Shi (2003), Li and Yang (2004), Li and Li (2006), Li and Baker (2007), Li, Baker and Fang (2007), Baker, Stephenson and Li (2008a), and Li et al. (2008). 2.2.3 Quantum Back-Action Limit The Standard Quantum Limit (SQL) will be introduced and reviewed in this section (Stephenson, 2009b), and design of the Li-Baker HFGW Detection System will also be reviewed to understand how the SQL might limit the sensitivity of this new type of GW detector. Review of the Standard Quantum Limit The Standard Quantum Limit (SQL) is o~en defined as "The limit on measurement accuracy at quantum scales due to back-action effects." But what is "back-action"? (See Kippenberg and Vahala, 2008.) From Clerk (2008) the Heisenberg Uncertainty Principle is (me) x (Llp) > fl/2 (3) 16 UNCLASSIFIED/ ;re~ err1e11111e l!l!ii! e,11,~·
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Report, from the dia collection. The PDF is mirrored here; the original link is above. 57 pages are in the text index: search them above, or from the library's search.