TY - CPAPER
AU - Marks, H. S.
AU - Borodin, D.
AU - Damti, A.
AU - Einat, M.
AU - Friedman, A.
AU - Gover, A.
AU - Kanter, M.
AU - Kleinman, H.
AU - Lasser, Y.
AU - Lurie, Yu.
AU - Vashdi, Y.
AU - Yahalom, A.
TI - Saturation Dynamics, Fine Spectrum, and Chirp Control in a CW FEL Oscillator
J2 - Proc. of FEL2015
AB - As in conventional laser physics, the saturation dynamics of a long-pulse Electrostatic Accelerator FEL (EA-FEL) oscillator consists of oscillations build-up, resonator modes competition, and establishment of narrow linewidth single mode lasing. In EA-FEL the gain curve drifts to lower frequencies during the long laser pulse due to inevitable droop in the acceleration voltage. This post-saturation drift renders fine chirp of the single mode laser frequency due to the oscillator frequency pulling effect. We have integrated a voltage-ramping element into the electrostatic accelerator terminal that makes it possible to control the acceleration voltage throughout the lasing pulse. This allows us to keep the voltage constant throughout the e-beam pulse, and so increase the single mode lasing time, avoiding mode-hopping during the pulse due to the drift of the gain curve. Furthermore, by adjusting the voltage ramp rate and polarity we obtained controllable positive/negative laser frequency chirp that can be used in a single pulse sweep for fine spectral line (10⁻⁶) gas-spectroscopy. The study was conducted on the Israeli EA-FEL that operates at tunable frequencies between 95-110 GHz.
PB - JACoW
CY - Geneva, Switzerland
SP - 580
EP - 582
KW - FEL
KW - laser
KW - electron
KW - coupling
KW - operation
DA - 2015/12
PY - 2015
SN - 978-3-95450-134-2
DO - 10.18429/JACoW-FEL2015-WEB04
UR - http://accelconf.web.cern.ch/AccelConf/FEL2015/papers/web04.pdf
ER -