Modern Laser for High Energy Particle Acceleration: A long term view Gérard Mourou Institut de Lumière Extreme EUROnnac CERN 3 May 2011

Contents Low Luminosity Paradigm High Luminosity Paradigm(collider) Single shot PeV High-Energy particle Laser Low Rep. Rate High Energy Laser MJ, Low Average power. 100W High Luminosity Paradigm(collider) Recurrent Laser 15 kHz, High average Power 500MW Search for the Efficient Laser Driver Thin disk laser Fiber laser (CAN Coherent Amplification Net work) ICAN(International Coherent Amplification Network)

Towards the PeV single Shot Using MJ laser At 1joule per GeV, a laser Megajoule laser after compression to the ps Level could produce PeV particles. Physics: Texture of Vacuum and testing General Relativity

High Luminosity Paradigme Collider Application Recurrent Laser, 15 kHz and GW Average Power

Energy vs. Rep. Rate Wahoo!! 1 Stage, .5MW, 32J, 17kHz 0.5GW , 5GeV Collider ( 2x 500Stages) Wahoo!! 10 M J 1 Stage, .5MW, 32J, 17kHz LMJ/NIF 1 M J 1 kW de puissance moyenne 100 k J LIL 10 k J 1 k J LULI 2000 pico 2000 150J/.1Hz Jena Energie par impulsion 100 J LULI 100J/10Hz Luli 10 J 1 W de puissance moyenne LULI 100TW 1 J Commercial 0,1 J 104 10 -5 10 -4 10 -3 10 -2 10 -1 1 10 10 2 Taux de répetition (Hz)

Here the efficiency is at a premium! 1 GW consumption means an electric bill of a 1B€/year 1% difference in efficiency cost 10-20M€/year

Search for High Average Power and Efficient Driver Laser Thin Disk Fiber Amplifier

Thin Disk laser Driver

Fiber Laser Driver

Fiber vs. Bulk lasers High Gain fiber amplifiers allow ~ 50% total plug-to-optical output efficiency reachable Single mode fiber amplifier have reached 10kW optical power. large bandwidth (100fs) High rep. rate 10kHz>1/tf, highly desirable for diode stability, lifetime and system noise excellent beam quality efficient, diode-pumped operation Pigtail pumping vs stacks high single pass gain They can be mass-produced at low cost.

Pigtailed pumped instead of stack laser pumped Fiber laser Pigtailed pumped instead of stack laser pumped Diode pump active core inner cladding refractive index profile laser radiation Øco Øcl Single mode Øco~10 outer cladding n Pigtailed

The CAN concept, opening to the scalability  Laser concept based on a diode-pumped fiber network of femtosecond pulses  Device possibly based on standard, cheap and reliable telecom components - Laser architecture allowing high peak / high average powers are desired for future societal application Coherent combining demonstrated for CW regime, few experiments in ns regime, no results yet in fs regime Coherent combining required for some application not for all of them Bridgelab Symposium for Laser Acceleration – Paris, January 14, 2011 – Matthieu Somekh

500x1.0 MW Fiber bundles 1mJ/fiber x 15kHz=15W 1MW/15W/fiber= 70 103 Fibers/bundles They will be all coherently phased. Electron/positron beam Transport fibers ~1mm ~70cm Length of a fiber ~2m Total fiber length~ 5 104km

The CAN Project: (a ANR-National Project)

64-Fiber Mock-up Insertion des fibres Insertion des fibres Insertion des 64 fibres, alignement PM (° près), collage Polissage collectif de la surface de sortie des fibres Composant intégré pour le maintien des fibres 31 Mai 2010 – Soutenance de thèse – C. Bellanger

Matrice de microlentilles 31 Mai 2010 – Soutenance de thèse – C. Bellanger Caractéristiques F = 5,7mm Réalisation par lithographie 20µm ± 1µm 1500 µm ± 1µm Mesure du pas

Comparaison avec la sphère théorique Matrice de microlentilles 31 Mai 2010 – Soutenance de thèse – C. Bellanger Mesure du profil Profil (mm) -5 -10 --- Sphère théorique --- Profil mesuré Comparaison avec la sphère théorique λ / 10 sur 80% de l’ouverture λ / 3 sur la totalité 0,0 0,5 1,0 1,5 (mm)

Phase control

Génération des 64 faisceaux 31 Mai 2010 – Soutenance de thèse – C. Bellanger Génération de 64 faisceaux fibrés Ampli 1 W 1 vers 16 PM DL l=1,5µm Contrôleur de polar Ampli 1 W PM

Insertion des fibres Toron de 64 fibres réalisé 31 Mai 2010 – Soutenance de thèse – C. Bellanger Toron de 64 fibres réalisé

Wave-front Measurement

Généralités sur l’IDQL IDQL: Interféromètre à Décalage Quadri-Latéral Technique d’analyse de front d’onde auto-référencée Principe: analyse de l’interférence du front d’onde avec lui même après duplication et décalage latéral k1,1 s k-1,1 s k1,-1 k-1,-1 s zd s z Aberration sphérique Utilisations usuelles: Métrologie optique, caractérisation laser, optique adaptative sur des surfaces continues Fonctionne également sur des surfaces segmentées (marches de phase)

Expérimentalement Caméra Réseau Lentille 31 Mai 2010 – Soutenance de thèse – C. Bellanger Avec notre analyseur expérimental: ajout d’une lentille d’imagerie Nécessité d’adapter la taille de la matrice de faisceaux (grandissement g) Nécessité d’éliminer l’effet de la divergence des faisceaux gaussiens au niveau du détecteur (conservation de la lacunarité) d di Caméra Réseau Lentille Condition:

Analyse de l’interférogramme 31 Mai 2010 – Soutenance de thèse – C. Bellanger Jeux de franges de même pas dans les deux sens Déphasage entre deux fibres adjacentes codé dans le déplacement des franges Analyse du déplacement relatif des franges Sinusoïdes  Démodulation synchrone spatiale sur toute la figure Récupération des 7x8 8x7 valeurs de différences Reconstruction de la cartographie de phase matriciellement Interférogramme expérimental Gradient X Gradient Y

64 CW fibers have been phased (Private com. A. Brignon Thales)

Phase Locking in the Femtosecond Regime

CAN recent results / phase locking technique In the femto second Combining efficiency > 90% L. Daniault, M. Hanna, L. Lombard, D. Goular, P. Bourdon, F. Druon, P. Georges “Coherent combining of two femtosecond fiber chirped pulse amplifiers“ Oral : Advanced Solid State Photonics, ASSP 2011, Istanbul, Turkey  (February 13-16 2011) Accepted: Optics Letters, L. Daniault et al, « Coherent beam combining of two femtosecond fiber chirped pulse amplifiers » - Small modulation at a high frequency is added to the feedback signal - The resulting intensity modulation depends on the operation point - Subsequent lock-in amplifier and PID gives an error signal Bridgelab Symposium for Laser Acceleration – Paris, January 14, 2011 – Matthieu Somekh

CAN recent results / phase locking technique (2) the recent results on phase locking are very nice, and their novelty has to be emphasised Autocorrelations 325 fs pulsewidth Spectra 4.3 nm FWHM Bridgelab Symposium for Laser Acceleration – Paris, January 14, 2011 – Matthieu Somekh

Diode cost Stacks Laser Diode 20000 hours Pigtailed Diode

Fiber pigtailed single emitters VS stacks Cost in € / Watt 2D Stacks Fibered emitters 3.5 B€ in laser diodes

Fiber pigtailed single emitters VS stacks Cost in € / Watt / year Stacks 2D Emetteurs fibrés Assump.: - 1 year = 200 days ; 24 hours per day - lifetime: stacks = 20.000 h ; fiber pigtailed single emitters = 50.000 h

The International Coherent Amplification Initiative CERN Different communities joining their efforts towards the collaborative evaluation of the fiber CAN concept as one of the possible solutions for the next laser-based driver generation: Laser & fibre communities High energy physics community  Final goal : definition, conception, design and realisation of such a laser Bridgelab Symposium for Laser Acceleration – Paris, January 14, 2011 – Matthieu Somekh

A first targeted step of 2 years 1 proposal submitted to Brussels (Type of funding scheme: Coordination and support actions (Supporting)) 18 participants from laser, fibre and high energy physics communities already behind the ICAN project To be organized in 2012-2013 : Conferences Workshops The proposal has been Favorably Rated by the EU Bridgelab Symposium for Laser Acceleration – Paris, January 14, 2011 – Matthieu Somekh

Conclusions Low luminosity Paradigm: PeV particles, single shot could be produced by laser acceleration. High Luminosity Paradigme: Preliminary studies with CAN have demonstrated that the possibility to build an efficient laser driver for a GW, TeV, collider seems at this point possible . The ICAN program in 18 months hopefully will help us to confirm this opinion

Laser Acceleration-Telecom Cycle Coherent Amplifying Network+ Laser Wake Field WWW Tim Berners-Lee Optical Fiber Charles Kao

Acknowledgements to our Fiber Accelerator Team Toshiki Tajima, ILE, MPQ, Garching: Laser acceleration Jean-Pierre Koutchouk, CERN: Accelerator Almantas Galvanauskas U. Michigan: Fiber amplification Johan Nilsson, ORC, U. Southampton: fiber amplification, fabrication: Marc Hanna: Institut d’ optique: Fibers Phasing Vincent Michau ONERA: Fiber Phasing Matthieu Somekh Ecole Polytechnique: Diode laser Catherine Sarrazin: Adminsitrative Assistant Institut Lumière Extrême

The Moral of this talk HighPeak Power High Average Power Telecom

Fibre laser strengths & limitations   - Initial & running cost - Reliability / Robustness - Maintenance - Footprint - Frequency - Beam Quality - Scalability of the energy in a single fibre in short pulse laser operation Bridgelab Symposium for Laser Acceleration – Paris, January 14, 2011 – Matthieu Somekh

Can technology obey Moore’s Law? Yes for Patterned Structures. Bob Beyers’dictum