Title :
Noise properties of microwave signals synthesized with femtosecond lasers
Author :
Ivanov, Eugene N. ; McFerran, John J. ; Diddams, Scott A. ; Hollberg, Leo
Author_Institution :
Sch. of Phys., Western Australia Univ., Crawley, WA
fDate :
4/1/2007 12:00:00 AM
Abstract :
We discuss various aspects of high resolution measurements of phase fluctuations at microwave frequencies. This includes methods to achieve thermal noise limited sensitivity, along with the improved immunity to oscillator amplitude noise. A few prototype measurement systems were developed to measure phase fluctuations of microwave signals extracted from the optical pulse trains generated by femtosecond lasers. This enabled first reliable measurements of the excess phase noise associated with optical-to-microwave frequency division. The spectral density of the excess phase noise was found to be -140 dBc/Hz at 100 Hz offset from the 10 GHz carrier which was almost 40 dB better than that of a high quality microwave synthesizer
Keywords :
fluctuations; high-speed optical techniques; microwave measurement; microwave photonics; noise measurement; phase noise; thermal noise; 10 GHz; 100 Hz; femtosecond lasers; high resolution measurements; microwave signals; noise properties; optical pulse trains; optical-to-microwave frequency division; oscillator amplitude noise immunity; phase fluctuations; phase noise; spectral density; thermal noise limited sensitivity; Fluctuations; Frequency measurement; Laser noise; Masers; Microwave measurements; Noise level; Optical noise; Phase measurement; Signal synthesis; Ultrafast optics;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
DOI :
10.1109/TUFFC.2007.307
