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Doctoral Thesis
DOI
10.11606/T.43.2006.tde-09022007-125340
Document
Author
Full name
Ricardo Elgul Samad
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
São Paulo, 2006
Supervisor
Committee
Vieira Junior, Nilson Dias (President)
Figueiredo Neto, Antonio Martins
Nussenzveig, Paulo Alberto
Schwab, Carlos
Zilio, Sergio Carlos
Title in Portuguese
"Desenvolvimento de um amplificador de pulsos ultracurtos de Cr:LiSAF para um sistema laser híbrido de alta potência"
Keywords in Portuguese
Amplificadores ópticos
Lase do estado sólido
Pulsos ultracurtos
Abstract in Portuguese
Foi desenvolvida e construída uma cavidade bombeadora para um meio de ganho de Cr:LiSAF na forma de bastão, bombeado por duas lâmpadas, visando sua operação como amplificador de pulsos ultracurtos a taxas de repetição elevadas, e com redução da carga térmica sobre o meio de ganho. A cavidade e o meio de ganho foram caracterizados sob operação como laser e como amplificador de pulsos ultracurtos. Atuando como laser, obtivemos 30 Hz de taxa de repetição e 20 W de potência média, resultado inédito, e ganho máximo de 1,5 por passagem. Alterando as características do bombeamento, foi possível operar o laser a 8 Hz e 16 W de potência média, com ganho máximo de 3,6 por passagem. A cavidade bombeadora, na configuração de maior ganho, foi integrada e sincronizada a um sistema Chirped Pulse Amplification baseado em cristais de Ti:Safira, concebido e construído visando a sua conjugação com o amplificador de Cr:LiSAF. O amplficiador introduziu um fator de amplificação de 150 em pulsos de 20 ps, produzindo pulsos com potência de pico de 0,5 TW. Também foi apresentada uma nova técnica para medida do limiar de ablação por pulsos ultracurtos, e sua teoria analítica foi desenvolvida. Esta técnica foi utilizada na determinação do limiar de ablação de cristais de Cr:LiSAF no regime de 20 ps.
Title in English
Development of a Cr:LISAF ultrashort pulse amplifier for a high hybrid laser system
Keywords in English
Optical amplifiers
Solid state lasers
Ultrashort pulses
Abstract in English
We have developed and built a pumping cavity for a Cr:LiSAF rod, pumped by two flashlamps, in order to operate it as an ultrashort laser pulse amplifier at the highest possible repetition rate, under reduced thermal load. The pumping cavity and the gain medium were characterized under laser and ultrashort pulse amplifier operation. Operating as a laser, 30 Hz repetition rate and 20 W average power were obtained for the first time at a maximum gain per pass of 1.5. Changing the pumping characteristics, the laser provided 16 W at 8 Hz repetition rate, at a maximum gain of 3.6. The cavity, in the highest gain configuration, was integrated and synchronized to a Ti:Sapphire Chirped Pulse Amplification system, conceived and built to comprise the Cr:LiSAF amplifier. The amplifier provided amplification by a factor 150 to the 20 ps stretched pulses, resulting in pulses with 0.5 TW of peak power. Also, a new technique to measure ultrashort pulses ablation threshold was presented, and its analytical theory was developed. This technique was used to determine the ablation threshold for Cr:LiSAF crystals in the 20 ps regime.
 
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1522809.pdf (8.52 Mbytes)
Publishing Date
2007-03-15
 
WARNING: The material described below relates to works resulting from this thesis or dissertation. The contents of these works are the author's responsibility.
  • SAMAD, R. E., and VIEIRA JR., N. D.. Geometrical method for determining the surface damage threshold for femtosecond laser pulses [doi:10.1134/S1054660X06020228]. Laser Physics [online], 2006, vol. 16, n. 2, p. 336-339.
  • SAMAD, Ricardo Elgul, et al. 30 W Cr:LiSrAlF6 flashlamp-pumped pulsed laser [doi:10.1364/OL.32.000050]. Optics Letters [online], 2007, vol. 32, n. 1, p. 50-52.
  • SAMAD, Ricardo Elgul, et al. 5 Hz flashlamp pumped Cr:LiSAF multipass amplifier for ultrashort pulses [doi:10.1088/1464-4258/10/10/104010]. Journal of Optics A: Pure and Applied Optics [online], 2008, vol. 10, n. 10, p. 104010.
  • SAMAD, Ricardo Elgul, et al. Development of a flashlamp-pumped Cr:LiSAF laser operating at 30 Hz [doi:10.1364/AO.45.003356]. Applied Optics [online], 2006, vol. 45, n. 14, p. 3356-3360.
  • SAMAD, Ricardo Elgul, BALDOCHI, Sonia Licia, and VIEIRA, JR., Nilson Dias. Diagonal scan measurement of Cr:LiSAF 20 ps ablation threshold [doi:10.1364/AO.47.000920]. Applied Optics [online], 2008, vol. 47, n. 7, p. 920.
  • SAMAD, Ricardo E., et al. Amplification of ultrashort pulses to 0.5 TW at 5 Hz with a flashlamp pumped Cr:LiSAF gain medium [doi:10.1117/12.699130]. In Proceedings of SPIE [online], San Jose, CA, USA, 2007. San Jose, CA, USA : SPIE, 2007. vol. 6451, p. 645112-645.
  • SAMAD, Ricardo E., BALDOCHI, Sonia L., and VIEIRA, JR., Nilson D.. Determination of Cr:LiSAF crystals ablation thresholds on the 20 ps regime using a diagonal scan [doi:10.1117/12.699156]. In Proceedings of SPIE [online], San Jose, CA, USA, 2007. San Jose, CA, USA : SPIE, 2007. vol. 6451, p. 64511C-645.
  • SAMAD, Ricardo Elgul, et al. Development of a lamp-pumped Cr:LiSAF laser operating at 20Hz for a terawatt CPA system [doi:10.1117/12.644145]. In Proceedings of SPIE [online], San Jose, CA, USA, 2006. San Jose, CA, USA : SPIE, 2006. vol. 6101, p. 610112-610.
  • SAMAD, Ricardo Elgul, et al. Development of a TW Level Cr:LiSAF Multipass Amplifier [doi:10.1063/1.2926894]. In AIP Conference Proceedings [online], Campinas, São Paulo (Brazil), 2008. Campinas, São Paulo (Brazil) : AIP, 2008. vol. 992, p. 398-402.
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