Title :
Spectral purity and sources of noise in femtosecond-demodulation terahertz sources driven by Ti:sapphire mode-locked lasers
Author :
Demers, J.R. ; Goyette, Tom M. ; Ferrio, Kyle B. ; Everitt, Henry O. ; Guenther, Bobby D. ; De Lucia, Frank C.
Author_Institution :
Dept. of Phys., Ohio State Univ., Columbus, OH, USA
fDate :
4/1/2001 12:00:00 AM
Abstract :
Direct measurements of the spectral purity in terahertz femtosecond-demodulation sources are reported and compared to theory. Because these sources operate at very high harmonics (~102-104) of the mode-lock frequency, a high spectral purity source is very dependent on a low-jitter femtosecond laser. Conversely, the spectral content of the terahertz sources provides detailed information about timing jitter and stringent tests of models used to describe the jitter. We find that both the behavior of the central core, and the noise skirts of the power spectrum of our sources, can be quantitatively related to measured ripple and continuum amplitude noise on the Ar+ pump laser by use of modulation theory
Keywords :
demodulation; high-speed optical techniques; laser mode locking; laser noise; microwave photonics; solid lasers; submillimetre wave generation; timing jitter; Al2O3:Ti; Ar; Ar+ pump laser; Ti:sapphire mode-locked lasers; central core; continuum amplitude noise; direct measurements; femtosecond-demodulation terahertz sources; low-jitter femtosecond laser; mode-lock frequency; modulation theory; noise skirts; noise sources; power spectrum; ripple; spectral content; spectral purity; timing jitter; very high harmonics; Frequency; Laser mode locking; Laser noise; Laser theory; Noise level; Noise measurement; Power measurement; Submillimeter wave measurements; Testing; Timing jitter;
Journal_Title :
Quantum Electronics, IEEE Journal of
