Abstract

Generating multi-GHz clock signals with low phase noise is a fundamental challenge in many domains including electronic instrumentation, radar ranging, telecommunication, signal intelligence or radio-astronomy. Generating high-frequency signals from low frequency oscillators by conventional analog frequency multiplication is hampered by the intrinsic phase noise degradation of the multiplication process itself (i.e. 20 log(q), where q is the multiplicative factor). Conversely, photonics offers efficient sources of multi-GHz signals using frequency combs or harmonic mode-locking, but at the price of complexity and large electronic resources. Recently, a technique of frequency multiplication based on an acousto-optic frequency shifting loop has been reported, allowing the multiplication of an RF signal at 80 MHz by factors up to 100 [1].

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