hock-timing Measurements in ctly Driven Spherical ICF Targets

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1 Spectrometer wo-beam SPIDER for dual-pulse single-shot characterization Doug French1, Christophe Dorrer2, and Igor Jovanovic1 hock-iming Measurements in ctly Driven Spherical ICF argets 1Department of Mechanical and Nuclear Engineering, he Pennsylvania State University 2Laboratory for Laser Energetics, University of Rochester 28 September 2010 VISAR Data 1st shock 1st shock in CD shell in D2

2 Outline Motivation and potential applications wo-beam SPIDER (-SPIDER) S R 2" R S D1 SWP Spectrometer - Optical layout Prism P - Experimental validation -SPIDER for phase amplification experiment Conclusions Grating G E Etalon S - Stretched beam R - Replica beam (a)! D2 LWP M Mirror - op beam - ottom beam 28 September

3 Simultaneous temporal characterization of multiple pulses can benefit ultrahigh intensity laser experiments Pulse characterization/diagnostics in ultrahigh intensity systems Diagnostics Multi-beam probing of dynamic processes τ τ Diagnostics September

4 Multiple pulses can be measured by multiple instruments, but more convenient solutions are desired Multiple instruments Single instrument with multiple beams Diagnostics Diagnostics Diagnostics Diagnostics Diagnostics Large footprint Expensive Smaller footprint Less expensive Difficult/time-consuming to align 28 September

5 Candidate techniques for multiplexed temporal characterization FROG G E M D2 REEFROG exists for twin-beam measurement 2D CCD P Single-shot requires time-space encoding, which can be difficult for distorted beams Spectrometer Requires 2D spectrometer 28 September D1 R S 2" S R

6 ues for ultrashort pulse characterization are spectral phase interferometry for direct Candidate techniques for multiplexed temporal characterization (2) field reconstruction (SPIDER) and frequency-resolved optical gating (FROG). We trate a novel design of the SPIDER technique, SPIDER two-beam SPIDER (-SPIDER) [1], EEE JOURNAL OF QUANUM ELECRONICS, VOL. 35, NO. 4, APRIL 1999 imultaneously measures the electric field of two pulses, reference and probe, on a single M d by calculating the spectral phase difference of the two pulses is able to compensate E G ematic shot-to-shot phase variations originating from the laser system. C. Iaconis, Opt. Lett. 23, 1998 Only requires 1D spectrometer for traditional implementation D2. 4. he SPIDER apparatus. wo pulse replicas that are delayed with pect to one another by are frequency mixed with a chirped pulse in onlinear crystal. Each pulse replica is frequency mixed with a different e slice, and hence spectral slice, of the stretched pulse, and, consequently, upconverted pulses are spectrally sheared. he resulting interferogram is olved with a spectrometer. 1D CCD P eans of averaging Vertical over multiplexing the many data sets available in a sine interferogram. provides he spectral a convenient step size of the data is usually uch smaller method than the shear, for multi-beam and, consequently, concatenation measurement es only a subset of the available data. Integration, in contrast, es all of the data. Of course, one can construct many sets the sampled spectral phase by starting the concatenation at fferent frequencies, e.g., then ing each sampled set to reconstruct the analytic signal, and Spectrometer 28 September D1 R S 2" S R

7 Implementation of -SPIDER S R R S S R R S S - Stretched beam R - Replica beams P Prism 2" ype II O 0.5 mm thick D1 SWP Spectrometer 0.3 nm resolution D2 LWP G 600 g/mm ϕ (2) = 1.19 ps/hz E Etalon L ~ 200 µm (a) 28 September 2010! τ = 1.92 ps 7 M Mirror - op beam - ottom beam

8 -SPIDER experimental layout Spectrometer 28 September

9 -SPIDER user interface 28 September

10 -SPIDER data acquisition and analysis he 2D spectrometer has additional degrees of freedom for alignment Ideal image from spectrometer: Imaging system in the spectrometer can lead to curved field lines at the extremities of the image: y Forbidden Restricting beams to the center region of the entrance slit minimizes curvature Independent λ calibration for each beam Forbidden Allowed λ 28 September

11 Experimental validation of -SPIDER i:sapphire Laser Measure dispersion for 10cm of glass φ(ω) Reference Probe -SPIDER Phase rad Λ nm Intensity a.u. 28 September Intensity a.u ! D. French, Opt. Lett., 34, Delay fs

12 -SPIDER was deployed as a diagnostic for a singleshot phase amplification experiment Optical parametric amplification (OPA): Phase-sensitive OPA (PSOPA): ω3 ω1 OPA ω3 ω1 ω2 ω3 ω1 ω2 PSOPA ω3 ω1 ω2 -SPIDER RIDEN i: Sapph CPA CCD 90% Psignal "/2 "/2 10% "/2 50 nm/step Ppump PS-OPA 1 µm/step 2! Mirror Polarizer Dichroic Mirror 28 September

13 -SPIDER was deployed as a diagnostic for a singleshot phase amplification experiment (2) he phase-sensitive OPA acts as a phase amplifier rather than an energy amplifier Ideally: Δφout = G Δφin Calculation Measurement It a.u. Reference lack, Probe Red IΩ a.u Spectrum and Spectral Phase Amplified Initial 2 Π 4 Π 6 Π Π Ω 2Π Hz 0 ΦΩ rad Y. Yin, Phase-Sensitive emporal Pulse Shaping for Ultrahigh Intensity Lasers, WP4, Wed. 4:30 Φt rad t fs Reference lack, Probe Red t fs 28 September

14 ate a novel design of the technique, two-beam SPIDER ultaneously measures thespider electric field of two pulses, reference and( pr -SPIDER scaling for characterization of multiple pulses ultaneously measures the electric of twoofpulses, reference pr by calculating the spectral phase field difference the two pulses isand able by the spectral phase difference of the two pulses is able aticcalculating shot-to-shot phase variations originating from the laser system Design parameters matic shot-to-shot from the laser system angle ofvariations the nonlinearoriginating crystal - Acceptancephase - eam size and overlap 2ω Spectrometer entrance slit ) wo-beam SPIDER system schematic, M-mirror, E-etalon, G-grating, P-retroreflector, 2ω-s 28 September D1-short-wave pass dichroic mirror, D2-long-wave pass dichroic mirror. he insets show the rela

15 Conclusions Conclusions - -SPIDER is capable of simultaneously measuring the amplitude and phase of two pulses on a single shot - -SPIDER reduces systematic errors in measurements of the effect of experimental systems on spectral phase Future work - Expansion of this technique for more than two beams - Redesign to make it easier to align reference and probe pulse injection - Use as standard diagnostic for current/future experiments 28 September