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Mid-InfraRed Picosecond Laser Facility MIRPILAF - ISTC # 2521
Facility developed:
- High Pressure Amplifier of short laser pulses (up to 10 atm)
- Picosecond CO2-laser master oscillator (MO) with pulse power of 1 MW and pulse duration of 100 ps
- Equipment for recording of picosecond laser pulses
Mid-Infrared Picosecond Laser Facility is considered as a multi-atmosphere terawatt picosecond (TWps) CO2-laser being developed on a basis of "MO-Pre-A-PA" design.
Master oscillator schematic diagram, including apparatus for recording of the laser pulse characteristics
Hybrid ÑÎ2-laser
Laser characteristics:
- CO2:N2:He - 1:1:7 gas mixture
- specific energy input into a gas discharge - 220...300 J/l
- maximal peak power of the laser output > 0.8 MW
- pulse duration ~ 400 ns
Picosecond Nd-laser to control optical switches
Nd-laser characteristics:
- Output energy: 3...5 mJ
- Beam diameter: 2.8 cm
- Pulse duration: 1...2 ps
Ge optical switches
Generation of picosecond CO2-laser pulse with a variable pulse width by using of Ge optical switches controlled by picosecond Nd-laser pulses
Master oscillator units |
Controlling Nd-laser
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Streak camera
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Hybrid ÑÎ2-laser
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Up-conversion equipment
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Master oscillator pulse characteristics |
Hybrid CO2-laser pulse passed through Ge-switch (upper track),
and controling Nd-laser pulse (lower track).
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Master oscillator pulse registered
by a streak camera.
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Temporal profile (power temporal shape) of the master oscillator pulse
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Results
- Pulse width of the Master Oscillator pulse changes from 10 ps to 100 ps, depending on the delay between controlling pulses
- Maximal pulse peak power - 0.8 MW
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Fields of application of TWps CO2-lasers
| Super strong light fields |
Generation of ultra short laser pulses |
High-power laser ablation |
- Laser-guided lightning P ~ 1 TW, t ~ 100 ps...1 ns
- Laser acceleration of electrons P ~ 10 TW, t ~ 10 ps
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- X-ray picosecond pulses I~1016 W/cm2, t ~ 1 ps
- Multi-charged ions for acclerators I ~ 1015 W/cm2, t ~ 1 ps
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- Non-traditional recoverable power sources on the basis of laser ablation of metal oxides P~1 TW, t ~ 10 ps
- Creation of energy closed circuit
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| Schematic diagram of laser accelerator of electrons |
Plasma channel generated in the atmosphere by laser |
Generation of high-power ion beams |
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ÑÎ2-laser ring amplifier controlled by a Nd-laser.
Optical schematic diagram.
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Principal pulse characteristics of the amplifier:
- Laser beam aperture: up to 1.5 ñm
- Power amplification: 105-106
- Input pulse power: ~ 1 MW
- Output pulse power: > 100 GW (up to 0.5 TW)
- Output pulse width: ~ 10 ps
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Self-development of a single pulse out of a pulse train*
- unidirectional mode of radiation generation
- active medium with a reduced gas pressure of 3 atm
- power pumping pulse of 5 ms duration, providing multi-pass amplification (a(0)×z=90) of the laser pulse to maintain the self-development process
*V.T. Platonenko, V.D. Taranukhin. Coherent amplification of light pulses in a medium with a discrete spectrum. Quantum Electronics, Vol. 10, No. 11, 1983
ÑÎ2-laser ring amplifier controlled by a Nd-laser. Numerical model.
Theoretical model of the pre-amplifier is based on a numerical solution of a set of equations describing a) slowly oscillating amplitude
of electric field of a light wave propagating in the laser medium, b) active medium polarization, and c) population inversion.
It is assumed that an input pulse has a Gaussian temporal shape with a width of 5, 20, and 100 ps by å-2 intensity level.
It is assumed the signal shape does not change, and it meets the Gaussian self-reproducing beam with an area of 1 cm2 in the active
medium region. Amplitude of the input signal is equal to 6×105 V/m that corresponds to radiation intensity
of 105 W/cm2.
The laser medium is described by eleventh resonance spectral lines with a central one corresponding
to a wavelength of 10.59 mm. Polarization cross relaxation rate is assumed to be of Ò2 = 27 ps,
and molecular rotation relaxation rate is ÒR = 67 ps if the gas pressure is 3 atm. Saturation intensity is
of 270 MW/cm2 if the input pulse is of 100 ps. But the saturation intensity increases inversely a square of the pulse width.
Temporal shape transformations of the laser pulse propagating in the CO2-laser ring preamplifier
ÑÎ2-laser ring amplifier design
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Laser amplifier supply system parameters:
- Supply voltage pulse width: 5 ms
- Supply pulse energy: 3 kJ
- Amplifier active gas pressure: 3 atm
- Gas discharge gap: 3 cm
- Controlling Nd-laser pulse width: 10 ps
- Controlling Nd-laser pulse energy: ~ 300 mJ
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MIRPILAF, technical prospects
MIRPILAF, technical prospects (case A)
MIRPILAF, technical prospects (case B)
MIRPILAF, technical prospects (case C)
E-mail: contact@niioep.ru, http://www.niioep.ru
Copyright © 2007 NII OEP PLC (NIIKI OEP)
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