TY - GEN
T1 - Modeling of static and flowing-gas diode pumped alkali lasers
AU - Barmashenko, Boris D.
AU - Rosenwaks, Salman
PY - 2012/12/1
Y1 - 2012/12/1
N2 - A simple, semi-analytical model of diode pumped alkali lasers (DPALs), applicable to both static and flowing-gas devices, is reported. Unlike other models, assuming a 3-level scheme of the laser and neglecting influence of the temperature on the lasing power, it takes into account temperature rise and losses of alkali atoms due to ionization and chemical reactions, resulting in a decrease of the pump absorption and slope efficiency. The applicability of the model is demonstrated by (1) obtaining good agreement with measurements in a static DPAL [B.V. Zhdanov, J. Sell and R.J. Knize, Electron. Lett. 44, 582 (2008)], (2) predicting the dependence of power on the flow velocity in flowing-gas DPALs and (3) checking the effect of using a buffer gas with high molar heat capacity and large relaxation rate constant between the 2 P 3/2 and 2 P 1/2 fine-structure levels of the of the alkali atom. It is found that ionization processes have a small effect on the laser operation, whereas chemical reactions of alkali atoms with hydrocarbons strongly affect the lasing power. The power strongly increases with flow velocity and by replacing, e.g., ethane by propane as a buffer gas the power may be further increased by up to 30%. 8 kW is achievable for 20 kW pump at flow velocity of 20 m/s.
AB - A simple, semi-analytical model of diode pumped alkali lasers (DPALs), applicable to both static and flowing-gas devices, is reported. Unlike other models, assuming a 3-level scheme of the laser and neglecting influence of the temperature on the lasing power, it takes into account temperature rise and losses of alkali atoms due to ionization and chemical reactions, resulting in a decrease of the pump absorption and slope efficiency. The applicability of the model is demonstrated by (1) obtaining good agreement with measurements in a static DPAL [B.V. Zhdanov, J. Sell and R.J. Knize, Electron. Lett. 44, 582 (2008)], (2) predicting the dependence of power on the flow velocity in flowing-gas DPALs and (3) checking the effect of using a buffer gas with high molar heat capacity and large relaxation rate constant between the 2 P 3/2 and 2 P 1/2 fine-structure levels of the of the alkali atom. It is found that ionization processes have a small effect on the laser operation, whereas chemical reactions of alkali atoms with hydrocarbons strongly affect the lasing power. The power strongly increases with flow velocity and by replacing, e.g., ethane by propane as a buffer gas the power may be further increased by up to 30%. 8 kW is achievable for 20 kW pump at flow velocity of 20 m/s.
KW - diode pumping
KW - gas flows
KW - gas lasers
UR - http://www.scopus.com/inward/record.url?scp=84875740749&partnerID=8YFLogxK
U2 - https://doi.org/10.1117/12.973771
DO - https://doi.org/10.1117/12.973771
M3 - Conference contribution
SN - 9780819492883
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - High-Power Lasers 2012
T2 - High-Power Lasers 2012: Technology and Systems
Y2 - 24 September 2012 through 26 September 2012
ER -