Title :
Optimization of CO2 laser frequency stabilization via external Doppler dither modulation
Author :
Schupita, Walter ; Ullrich, Andreas ; Magerl, Gottfried
Author_Institution :
Inst. fuer Nachrichtentechnik und Hochfrequenztechnik, Tech. Univ. of Vienna, Austria
fDate :
10/1/1989 12:00:00 AM
Abstract :
An external Doppler dither modulation scheme for locking the CO 2 laser frequency to the center of the 4.2-μm fluorescence Lamb dip of CO2 is discussed. The optimum values for the frequency dither, fluorescence cell temperature and CO2 absorber gas pressure depending on the experimental conditions are determined. The design of two different dither mirror arrangements is described. With optimum parameters and with τ=40 ms integration time, it is possible to lock the CO2 laser to within ±10 kHz to line center over several minutes. Measurements of ultrahigh-resolution Lamb dip spectra of the υ2 as R (3,3) transition of NH3 show the superiority of external dither modulation over the conventional internal modulation scheme with respect to the spectral purity of the laser radiation
Keywords :
ammonia; carbon compounds; gas lasers; infrared spectra of polyatomic inorganic molecules; laser frequency stability; laser mode locking; laser transitions; mirrors; molecular fluorescence; optical design techniques; optical modulation; 4.2 micron; 40 ms; CO2 absorber gas pressure; CO2 laser frequency stabilization; NH3; NH3 R 3,3 transition; conventional internal modulation scheme; dither mirror design; external Doppler dither modulation; external dither modulation; fluorescence Lamb dip; fluorescence cell temperature; frequency dither; integration time; laser frequency locking; laser radiation; spectral purity; ultrahigh-resolution Lamb dip spectra; Fluorescence; Frequency modulation; Gas lasers; Laser beams; Laser stability; Laser transitions; Laser tuning; Mirrors; Structural beams; Temperature dependence;
Journal_Title :
Quantum Electronics, IEEE Journal of
