KEYWORDS: Pulsed laser operation, National Ignition Facility, High power lasers, Diagnostics, Photodiodes, Picosecond phenomena, Laser systems engineering, Data modeling, Photodetectors, Signal attenuation, Amplifiers
Accurate characterization of pulse contrast for high peak power lasers is critical to the success of experiments exploring inertial confinement fusion. The Advanced Radiographic Capability (ARC) laser at the National Ignition Facility (NIF) is a petawatt class laser system that produces pulses in the picosecond regime for the creation of diagnostic x-rays. ARC leverages four of the NIF’s beamlines for final amplification while implementing a separate front-end and pre-amplification stage, known as the High-Contrast ARC Front End (HCAFE). To characterize pulse contrast at the output of HCAFE, a means of measurement at long times (>500 ps) has been developed using a photodiode that has achieved a dynamic range of over 100 dB and 125 dB after deconvolution. Within hundreds of picoseconds of the main pulse, a commercial third-order cross-correlator (Amplitude Technologies Sequoia) is used to characterize the pulse contrast. Together, these diagnostics provide the necessary data for ensuring pulse contrast requirements can be met on ARC. Efforts were made to mitigate existing pre-pulses and to increase the stability of the system as a long-term operational companion to the NIF.
We describe the development and testing of the photodiode diagnostic and the analysis of the data resulting from contrast measurements. Details are also provided regarding the identification and mitigation of pre-pulses within the HCAFE system.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.