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Title: A traveling-wave forward coupler design for a new accelerating mode in a silicon woodpile accelerator

Silicon woodpile photonic crystals provide a base structure that can be used to build a three-dimensional dielectric waveguide system for high-gradient laser driven acceleration. A new woodpile waveguide design that hosts a phase synchronous, centrally confined accelerating mode is proposed. Comparing with previously discovered silicon woodpile accelerating modes, this mode shows advantages in terms of better electron beam loading and higher achievable acceleration gradient. Several traveling-wave coupler design schemes developed for multi-cell RF cavity accelerators are adapted to the woodpile power coupler design for this new accelerating mode. Design of a forward coupled, highly efficient silicon woodpile accelerator is achieved. Simulation shows high efficiency of over 75% of the drive laser power coupled to this fundamental accelerating mode, with less than 15% backward wave scattering. The estimated acceleration gradient, when the coupler structure is driven at the damage threshold fluence of silicon at its operating 1.506 μm wavelength, can reach 185 MV/m. Lastly, a 17-layer woodpile waveguide structure was successfully fabricated, and the measured bandgap is in excellent agreement with simulation.
 [1] ;  [2] ;  [1] ;  [1] ;  [2] ;  [1]
  1. SLAC National Accelerator Laboratory, Menlo Park, CA (United States)
  2. Purdue Univ., West Lafayette, IN (United States)
Publication Date:
Grant/Contract Number:
N66001-11-1-4199; AC02-76SF00515; FG02-13ER41970
Accepted Manuscript
Journal Name:
IEEE Journal of Selected Topics in Quantum Electronics
Additional Journal Information:
Journal Volume: 22; Journal Issue: 1; Journal ID: ISSN 1077-260X
IEEE Lasers and Electro-optics Society
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
43 PARTICLE ACCELERATORS; couplers; electron accelerators; optical waveguides; photonic crystals; silicon devices
OSTI Identifier: