A pulse repetition frequency scaling law for the high repetition rate neutral barium laser

High-repetition-frequency Q-switched laser is realized through adopting a Nd:LaMgAl11O19 (Nd:LMA) disordered crystal as the gain material, a laser diode lasing at 796 nm as the pumped source, and a semiconductor saturable absorber mirror (SESAM) as the Q-switched device. The output characteristics are analyzed under using different transmittance T plane mirrors as an output coupler. Without adopting SESAM, the laser is operating at a CW state, and a relatively high transmittance is helpful for achieving high output power, slope efficiency and light-to-light efficiency. For T = 7.5% and an absorbed power of 6.17 W, the output power arrives at its maximum of 1160 mW, and the corresponding slope efficiency and light-to-light efficiency are 20.71% and 18.78%, respectively. After introducing SESAM into the cavity, the laser operates at a passively Q-switched state, and the largest slope efficiency is 13.14% under T = 5.0%. Adopting five different output couplers, with the increase of the absorbed power, the pulse repetition frequencies, the pulse energies and the peak powers will ascend while the pulse widths will decline. The observed narrowest pulse width, the maximum pulse repetition frequency, the highest pulse energy and peak power are 1.745 μs, 175.88 kHz, 3.21 μJ and 1.84 W, respectively.

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Effect of acoustic waves on the repetition frequency of high repetition rate TEA-CO2 lasers and calculating optimization condition

Optics & Laser Technology ◽

10.1016/j.optlastec.2009.11.013 ◽

2010 ◽

Vol 42 (5) ◽

pp. 710-715 ◽

Cited By ~ 1

Author(s):

H.R. Baghshahi ◽

M. Rahimi

Keyword(s):

Repetition Rate ◽

Acoustic Waves ◽

High Repetition Rate ◽

Repetition Frequency ◽

Co2 Lasers ◽

High Repetition

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Ablation of Vitreous Tissue with a High Repetition Rate Erbium: YAG Laser

European Journal of Ophthalmology ◽

10.1177/112067210301300502 ◽

2003 ◽

Vol 13 (5) ◽

pp. 424-432 ◽

Cited By ~ 3

Author(s):

M.H.J. Krause ◽

D.J. D'Amico

Keyword(s):

Pulse Energy ◽

Repetition Rate ◽

Er:Yag Laser ◽

Nonlinear Effects ◽

High Repetition Rate ◽

Pulse Repetition ◽

Careful Examination ◽

Yag Laser ◽

High Repetition ◽

Pulse Energies

Purpose To quantify erbium (Er):YAG laser ablation of vitreous in relation to different pulse repetition rates ≤ 200 Hz, in order to examine the feasibility of laser for removal of vitreous gel (photovitrectomy) in clinically acceptable times. Methods Fresh porcine vitreous samples and saline controls were ablated in air with an Er:YAG laser connected to a sapphire fiber at pulse energies between 1.0 and 21.2 mJ and at pulse repetition rates between 10 and 200 Hz. Net ablation rates were determined by weight measurement. Results Reproducible and constant ablation rates were found for given laser parameters. Net ablation rates increased linearly with pulse repetition rate and nonlinearly with pulse energy. Expanded laser parameter domains permitted vitreous ablation rates as low as 1 μg/s to as high as 1031 μg/s. Ablation rates did not differ significantly between vitreous and saline. Conclusions The study documents clinically useful vitreous ablation rates that scale linearly with high repetition rates of Er:YAG laser, and suggests directions for further development of laser technology for enhanced removal of vitreous and other tissues. However, nonlinear effects of pulse energy also exist, indicating need for careful examination of ablation characteristics in various instruments.

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