# BELLA (laser)

The Berkeley Lab Laser Accelerator or BELLA is a laser built by the Thales Group and owned and operated by the Lawrence Berkeley National Laboratory.[1][2] On 20 July 2012 BELLA fired a 40 femtosecond laser pulse, establishing a world record for most powerful laser.[2][3]

BELLA was designed and built by Thales as part of the Laser and Optical Accelerator Systems Integrated Studies (LOASIS) program at LBNL. The LOASIS group studies the application of high-powered lasers to build compact particle accelerators. The BELLA laser was developed for the purposes of studying this principle.[2][3] The idea is that a laser which delivers a large amount of power in a very short pulse can cause ionization in a gas followed by plasma oscillation.[3] As a result the gas will emit electron bundles which can be used for medical imaging or materials research.[2][3]

On 20 July 2012, BELLA fired a laser pulses with a duration of 40 femtoseconds and a repetition frequency of 1 hertz. The pulses had a compressed output energy of 42.2 joule, making the power output of the laser 1 petawatt:

${42.2 J \over 40 fs} = {42.2 J \over 40*10^{-15} s} \approx 1*10^{15} J/s = 1 PW$

This result established BELLA as the most powerful laser in the world.[1][2][3]

## References

1. ^ a b "Petawatt Laser Achieves Record Power". Photonics.com. 1 August 2012. Retrieved 14 September 2012.
2. Paul Preuss (July 27, 2012). "BELLA Laser Achieves World Record Power at One Pulse Per Second". Berkely Lab News Letter. Lawrence Berkeley National Laboratory. Retrieved 14 September 2012.
3. Heirbaut, Jim (31 August 2012). "Surfen op plasmagolven" [Surfing on waves of plasma]. In van den Brink, Erwin. De Ingenieur (in Dutch) (Veen Magazines) 124 (13): 11. ISSN 0020-1146.