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Single-shot visualization of EVOLVING, light-speed index structures by multi-object phase contrast imaging. Zhengyan Li, Rafal Zgadzaj , Xiaoming Wang, Chih-Hao Pai , Yen-Yu Chang, Michael C. Downer Department of Physics, University of Texas at Austin, Austin, TX 78712. ∆ probe (r, ).
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Single-shot visualization of EVOLVING, light-speed index structures by multi-object phase contrast imaging Zhengyan Li, RafalZgadzaj, Xiaoming Wang, Chih-HaoPai, Yen-Yu Chang, Michael C. Downer Department of Physics, University of Texas at Austin, Austin, TX 78712 ∆probe(r,) aim of this work 120 µm 0.4 ps Snapshots of Quasi-static Wakes Movies of Evolving Wakes Captured in a Single Shot... 1 N. H. Matliset al., Nature Phys. 2, 749 (2006)
800 nm, compressed 30 fs(?), < 1 mJ probe pulse, w0 < 1cm The vacuum environment L1 = ? M2 1 deg. angle 35 cm interaction region? M1 OP4 OP1 OP2 OP3 L0 = ? Optical quality window? • What we want to do with index structure n(ζ,x,z)… • Multi-Object-Plane imaging, each object plane (OP) are imaged to different CCD. • Phase shift imprinted on probe at arbitrary z, not limited to OPs, is reconstructed. • In single shot, z-depending transverse profile at specific ζ is obtained. • With multi-shots, full visualization of index object n(ζ,x,z). • Questions: • Is the interaction length 35 cm, or longer? • Where is possible for us to couple laser into the chamber? What are the lengths of L0 and L1? To maintain a good imaging resolution, we hope L1 is not too large, what is the shortest length we can get? • Is there anything that potentially blocks or clips the beam between M1 and M2? Here the angle is 1 deg. = 0.0175 rad, so the inside diameter of the tube containing the laser has to be larger than 3 cm, if L0, L1 ~ 50 cm. Is it OK? Lens f = 75 cm CCD1 CCD2 CCD3 CCD4
Specs for MOPPCI in FACET • The minimum angle for oblique angle geometry θmin = λ/πσ = 0.146 deg @ σ = 100 um 0.72 deg @ σ = 20 um • Temporal walk-off Δt = Lθ2/2c = 38 fs @ θ = 0.5 deg 152 fs @ θ = 1 deg • z-resolution for evolving bubble δz = σ/θ = 5.73 mm @ σ = 100 um, θ= 1 deg 11.4 mm @ σ = 100 um, θ = 0.5 deg 2.29 mm @ σ = 20 um, θ = 0.5 deg • ζ-resolution and range for non-evolving bubble δζ = max{σ(θ/2+φ)/c, tpr}= max{50, 30} = 50 fs Δζ = Lθ(θ/2+φ)/c = 1.26 ps @ σ = 100 um, θ = 0.5 deg, φ = 8 deg