CFD DPAL modeling for various schemes of flow configurations

Comprehensive analysis of kinetic and fluid dynamic processes in flowing-gas diode pumped alkali lasers (DPALs) using two- and three-dimensional computational fluid dynamics (2D and 3D CFD) models is reported for Cs DPALs. The models take into account effects of temperature rise and losses of alkali atoms due to ionization. Various gas flow regimes and transverse and parallel flow-optics directions configurations are studied. Optimization of the Cs DPAL parameters, using 3D CFD modeling, shows that applying high flow velocity and narrowband pumping, maximum lasing power as high as 40 kW can be obtained at pump power of 80 kW for transverse flow configuration in a pumped volume of ~ 0.7 cm3. At high pump power the calculated laser power is higher for the transverse scheme than for the parallel scheme because of a more efficient heat convection from the beam volume in the transverse configuration. The CFD models are applied to experimental devices and the calculated results are in good agreement with the measurements.

[1]  Karol Waichman,et al.  Kinetic and fluid dynamic processes in diode pumped alkali lasers: semi-analytical and 2D and 3D CFD modeling , 2014, Photonics West - Lasers and Applications in Science and Engineering.

[2]  Mohamed S. El-Genk,et al.  Dissociative recombination coefficient for low temperature equilibrium cesium plasma , 2002 .

[3]  V. A. Eroshenko,et al.  Diode-pumped caesium vapour laser with closed-cycle laser-active medium circulation , 2012 .

[4]  Luc Barbier,et al.  Experimental study of Penning and Hornbeck-Molnar ionisation of rubidium atoms excited in a high s or d level (5d⩽nl⩽11s) , 1987 .

[5]  Boris D. Barmashenko,et al.  Feasibility of supersonic diode pumped alkali lasers: Model calculations , 2013 .

[6]  Xiaojun Xu,et al.  Modeling, numerical approach, and power scaling of alkali vapor lasers in side-pumped configuration with flowing medium , 2011 .

[7]  William F. Krupke,et al.  Diode pumped alkali lasers (DPALs)—A review (rev1) , 2012 .

[8]  Raymond J. Beach,et al.  New class of cw high-power diode-pumped alkali lasers (DPALs) (Plenary Paper) , 2004, SPIE High-Power Laser Ablation.

[9]  Weihong Hua,et al.  Theoretical model and novel numerical approach of a broadband optically pumped three-level alkali vapour laser , 2011 .

[10]  Boris V. Zhdanov,et al.  Review of alkali laser research and development , 2012 .

[11]  Karol Waichman,et al.  Semi-analytical and 3D CFD DPAL modeling: feasibility of supersonic operation , 2014, Photonics West - Lasers and Applications in Science and Engineering.

[12]  B. Barmashenko,et al.  Analysis of lasing in gas-flow lasers with stable resonators. , 1998, Applied optics.

[13]  V. K. Kanz,et al.  End-pumped continuous-wave alkali vapor lasers: experiment, model, and power scaling , 2004 .

[14]  Boris V. Zhdanov,et al.  Multiple laser diode array pumped Cs laser with 48W output power , 2008 .

[15]  G. Perram,et al.  A three-level analytic model for alkali metal vapor lasers: part I. Narrowband optical pumping , 2010 .

[16]  Boris D. Barmashenko,et al.  Detailed analysis of kinetic and fluid dynamic processes in diode-pumped alkali lasers , 2013 .

[17]  David L. Carroll,et al.  Role of excited state photoionization in the 852.1 nm Cs laser pumped by Cs-Ar photoassociation , 2013 .

[18]  Karol Waichman,et al.  Toward understanding the dissociation of I2 in chemical oxygen-iodine lasers: Combined experimental and theoretical studies , 2007 .

[19]  Jason Zweiback,et al.  Alkali-vapor lasers , 2010, LASE.

[20]  M. K. Shaffer,et al.  Photoionization in alkali lasers. , 2011, Optics express.

[21]  B. Barmashenko,et al.  Static diode pumped alkali lasers: Model calculations of the effects of heating, ionization, high electronic excitation and chemical reactions , 2013 .

[22]  Antonio Sasso,et al.  Laser ionization and time-resolved ion collection in cesium vapor , 1985 .

[23]  Timothy J. Madden,et al.  Simulation of deleterious processes in a static-cell diode pumped alkali laser , 2014, Photonics West - Lasers and Applications in Science and Engineering.

[24]  Karol Waichman,et al.  Comparison of semi-analytical to CFD model calculations and to experimental results of subsonic flowing-gas and static DPALs , 2014, Security and Defence.

[25]  Milosevic,et al.  Energy-pooling collisions in cesium: 6PJ+6PJ-->6S+(nl=7P,6D,8S,4F). , 1996, Physical review. A, Atomic, molecular, and optical physics.

[26]  G. Perram,et al.  A three-level model for alkali metal vapor lasers. Part II: broadband optical pumping , 2013 .

[27]  Glen P. Perram,et al.  Transfer between the cesium62P1/2and62P3/2levels induced by collisions with H2, HD, D2, CH4, C2H6, CF4, and C2F6 , 2011 .

[28]  B. Barmashenko,et al.  Modeling of flowing gas diode pumped alkali lasers: dependence of the operation on the gas velocity and on the nature of the buffer gas. , 2012, Optics letters.

[29]  Qi Zhu,et al.  Analysis of temperature distributions in diode-pumped alkali vapor lasers , 2010 .