Noise Properties of Microwave Signals Synthesized with Femtosecond Lasers
Eugene N. Ivanov, John J. McFerran, Scott A. Diddams, Leo W. Hollberg
We discuss various aspects of high resolution phase noise measurements at microwave frequencies. This includes methods to achieve thermal noise limited sensitivity and improved immunity to amplitude fluctuations of microwave signals. A few prototype measurement systems were developed for studying the phase fluctuations of microwave signals produced by demodulation of optical pulse trains generated by femtosecond lasers. With two femtosecond lasers phase-locked to the same stable laser the excess phase noise associated with optical-to-microwave frequency division was measured. The spectral density of the excess phase noise was found to be -140 dBc/Hz at 100 Hz offset from the carrier which was almost 40 dB better than achieved with the high quality microwave synthesizers.
Proc. 2005 Joint. Mtg. IEEE Intl. Freq. Cont. Symp. and PTTI
femtosecond lasers, frequency stabilisation, phase-locked loop
, McFerran, J.
, Diddams, S.
and Hollberg, L.
Noise Properties of Microwave Signals Synthesized with Femtosecond Lasers, Proc. 2005 Joint. Mtg. IEEE Intl. Freq. Cont. Symp. and PTTI, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=50281
(Accessed December 2, 2023)