About the possibility to build a 10-PW femtosecond laser
for ELI-NP till 2015
Razvan Dabu
National Institute for Lasers, Plasma and Radiation Physics
Bucharest
Workshop ELI-NP, Bucharest, March 11, 2011
Possible solutions for a 10-PW femtosecond laser system
A. Basic solution: High energy CPA in Ti:sapphire crystals.
B. Back-up solution: CPA in mixed Nd doped glasses (silicate &
phosphate glasses)
At present, both solutions involve technical difficulties and bottlenecks
Workshop ELI-NP, Bucharest, March 11, 2011
Solution A – bottlenecks and technical difficulties:
1. Large size Ti:sapphire crystals.
2. Large size, high damage threshold compression gratings.
3. Broad bandwidth high damage threshold high reflection dielectric
coatings.
4. Optically synchronized Front-End including high energy and high
repetition rate Yb:YAG pump lasers for OPCPA.
5. High repetition rate pump lasers for power amplifiers (including
technical solutions, large size LBO crystals for SHG, beam
homogenizers).
6. Large size adaptive optics.
Workshop ELI-NP, Bucharest, March 11, 2011
Solution B – bottlenecks and technical difficulties:
1. High energy short pulse amplification with sufficient bandwidth
to generate pulses of ~ 100 fs pulse duration.
2. Pulse compression of high energy (>1 kJ) pulses (tiled system
with high damage threshold multilayer dielectric gratings).
3. High intensity contrast (> 10^12) of the focused beams.
4. Thermal management of Nd:glass media for good repetition rate
(1 pulse/min – 1 pulse/10 sec).
5. Large size mirrors.
6. Large size adaptive optics.
Workshop ELI-NP, Bucharest, March 11, 2011
Risk evaluation
If we consider an optimistic probability of 80% for each of these 6
problems to be resolved in the next 2-3 years, the probability to
overcome the whole system bottlenecks and technical difficulties
is 26% until 2014.
For 90% → 53%
Moreover, there is an engineering question: it is possible to
accomplish the laser system development in the remaining time
till the end of 2015? It seems unlikely.
Workshop ELI-NP, Bucharest, March 11, 2011
Project implementation – version I
I. There is an entity (Company, Research Institute, International
Consortium, etc.) able to assume the risk to build till 2015 a laser
system with the following specifications?
Peak power ≥ 10 PW
Central wavelength: in the range 700-1100 nm
Pulse duration: < 150 fs
Repetition rate: higher than 1 pulse/min (higher than 1 pulse/10 s?)
Intensity contrast ≥ 10^12
Strehl ratio ≥ 0.6
Peak intensity of the focused beam ≥ 10^23 W/cm2.
Delivery time ≤ 48 months
under contract terms including:
- milestones;
- deliverables;
- acceptance tests;
- guarantee, penalties, repayment guarantee, etc.
Workshop ELI-NP, Bucharest, March 11, 2011
Project implementation – version II
II. Two-stage project implementation (in the frame of an
International Consortium managed by a Company with experience
in femtosecond laser systems manufacturing?):
First stage: contract for a 2- 4 PW (?) laser system development,
based on already existing techniques at T0 (project start moment),
with the deadline on the end of 2013 - middle of 2014 year.
Second stage: In the meantime (till 2014) and after 2014, R&D to
build a multi-PW laser with the target to reach 10 PW in 2015 or
later.
Workshop ELI-NP, Bucharest, March 11, 2011
CONCLUSIONS
1. Without delay: discussions with the potential producers to
find out if there is some entity able to assume the risk of
building a 10-PW laser system under a contract based on
well established conditions.
2. In case of a negative answer, to apply the two-stage project
implementation.
Workshop ELI-NP, Bucharest, March 11, 2011