LCLS-II Lasers


Infrastructure Preparation

The LCLS-II laser room will be located at the start of the linac at Sector 0, which was previously the site of the Collider Injector (CID). The site will be refurbished in order to accommodate the new laser lab, along with the beam transport to the RF Gun. Integral to this project has been strong interdepartmental collaboration as well as across five other institutions; JLAB, Fermilab, LBNL, ANL and Cornell University.

Injector Laser

The drive laser system will consist of a fiber oscillator and amplifier generating up to 50 W of class IV IR (1030 nm) radiation with UV conversion to produce the 4th harmonic (257.5 nm) of the IR beam.

Pump-Probe Lasers (OPCPA)

Repetition Rate ​0.1 MHz
​Pulse Energy 1 mJ (or 100 μJ at 1 MHz)​
​Wavelength Range ​0.7–1 μm
Energy Stability 1.5% rms​
​Pointing <10% of beam divergence
Pulse Duration​ ​15 fs
Compression 1.2 x BWL
Ellipticity >80%
Pulse Contrast 10-7 at >10 ps, 10-6 at > 1 ps
Sync, Stability <20 fs
Laser Drift Synch. <10 fs

We plan to use OPCPA techniques to develop a mJ-level Research and Development (R&D) laser amplifier system for high repetition rate free electron lasers. Development of a high repetition rate, high average power ultra-short laser source is compulsory for LCLS(-II) and will further enhance its unique capability.

Ultrafast laser amplifiers based on population inversion in an optical medium have so far been the only commercially available source for ultrashort pulses with average powers of several tens of Watts. However, the ultimate limit for these laser amplifiers is the heat load generated in the gain medium. Worth mentioning is also the gain narrowing, which ultimately limits the amplified pulse bandwidth. These drawbacks can be circumvented using to Optical Parametric Chirped Pulse Amplification (OPCPA). Optical Parametric Chirped Pulse Amplification is currently the most promising option, which offers as well a high degree of flexibility in terms of output pulse parameters. We are developing high average power OPCPA capabilities at SLAC using commercially available Yb:YAG amplifier technology for OPCPA pumping.


Pump-Probe Lasers (OPCPA)