Fig. 1. Principle and design of the TC-SSCC. (a) Schematic diagram for the temporal window of the THG-based SSCC (top view). The correlating pulse, intersecting with the under-test pulse, sampling pulse and optical axis by angles α, β and θ, respectively, is emitted perpendicularly to the crystal surface and is received by an N-pixel detector. PF_T (PF_S), pulse front of the under-test (sampling) pulse. (b) Schematic diagram for temporal resolution of the THG-based SSCC (top view). (c) ((d)) Calculated noncollinear angle α+β (blue), temporal window (black) and temporal resolution (red) as a function of angle θ under Type-I (Type-II) PM conditions in β-BBO crystals. The under-test and sampling pulses are at 800 and 400 nm, respectively. The two dashed lines in (c) mark the working points of the two channels of the TC-SSCC in the experiments.

Fig. 2. Schematic diagram of the TC–SSCC. DM, dichroic mirror, high reflection at 400 nm and high transmission at 800 nm; BS-1, beam splitter for 800 nm; BS-2, beam splitter for 400 nm; HWP, half-wave plate; HR, high reflection mirror for 800 nm; CLA, cylindrical lens assembly for beam shaping; Ag, silver mirrors; Au, gold mirrors; Al, aluminum mirrors; TS, translation stage; CL1 (CL3), cylindrical lens with f = 100 mm for imaging; CL2 (CL4), cylindrical lens with f = 30 mm for focusing; FA, fiber array with N = 100 channels; PMT, photomultiplier tube. Insets, beam profiles of FH under-test pulses before BS1 and SH sampling pulses before BS2.

Fig. 3. Temporal resolution characterization for the TC–SSCC. (a) Measured peak pulse by a DSCC (black), and channel-1 (blue) and channel-2 (red) of the TC–SSCC. (b) High-dynamic-range measurements on the peak pulse by a DSCC (black) and channel-2 of the TC–SSCC (red). The DSCC adopted a 25-fs scanning step.

Fig. 4. Large-window pulse-contrast measurement by channel-1 of the TC-SSCC (red curve with circles). Blue curve with circles, measurement by channel-1 of the TC-SSCC when the back-surface-wedged BS-2 was replaced by a 4-mm-thick non-wedged splitter. Green squares, expected prepulse locations caused by the non-wedged splitter. Black curve, DSCC measurement with a scanning step of 1 ps.

Fig. 5. Combination of two-channel measurements. Blue curve with circles, channel-2 measurement; red curve with circles, channel-1 measurement from –108 to –3 ps with a wedged BS-2; purple curve with circles, channel-1 measurement from –130 to –25 ps with a non-wedged BS-2; green squares, expected prepulse locations caused by the non-wedged splitter; black solid curve, DSCC measurement with a scanning step of 200 fs; black dashed line, minimum display of the oscilloscope.

Fig. 6. The TC-SSCC prototype device for the SG-II 5 PW laser. (a) Device photograph, uncovered side panels. (b) Data processing system, consisting of an oscilloscope and an analysis software.