STRIPED FISH Research Articles

Single-shot measurements of pulse-front tilt in intense ps laser pulses and its effect on accelerated electron and ion beam characteristics (invited).

We report recent single-shot spatiotemporal measurements of laser pulses, including pulse-front tilt (PFT) and spatial chirp, taken at the Compact Multipulse Terawatt laser at the Jupiter Laser Facility in Livermore, CA. STRIPED FISH, a device that measures the complete 3D electric field of fs to ps laser pulses on a single shot, was adapted to near infrared for these measurements. We present the design of the instrument used for these experiments, the on-shot measurements of systematic high-order PFT, and shot-to-shot variations in the measurements of spatiotemporal couplings. Finally, we simulate the effect of PFT in target normal sheath acceleration experiments. These simulations showed that pulse front tilt can steer hot electrons, shape the distribution of the accelerating sheath field, and increase the variability of cutoff energy in the resulting proton spectra. While these effects may be detrimental to experimental accuracy if the pulse front tilt is left unmeasured, hot electron steering shows promise for precision manipulation of the particle source for a range of applications, including irradiation of secondary targets for opacity measurements, radiography, or neutron generation.

Rapid retrieval of first-order spatiotemporal distortions for ultrashort laser pulses

High-intensity, ultrashort laser sources are a foundational pillar for High-Energy-Density (HED) physics, and as the repetition rates of these systems increase, diagnostics must be developed to match their data collection speed. Characterization of any spatiotemporal distortions in the laser pulse is necessary to standardize results across facilities. We have previously developed a laser diagnostic called spatially and temporally resolved intensity and phase evaluation device: full information from a single hologram, or STRIPED FISH, to measure the full spatiotemporal laser electric field on a single shot. In order to provide rapid feedback, we here adapt the STRIPED FISH retrieval algorithm, which typically has computation times of up to 30 min due to the high spatial resolution of the device and its retrieval of the complete four-dimensional pulse field, to distill the key electric field quantities into a handful of scalars for rapid assessment of the pulse’s 1st-order distortions. Here, our new, rapid non-iterative retrieval algorithm is validated with simulated and experimental data, and it provides, within seconds, the same 1st-order information as given by the full analysis. This algorithm is suitable for on-shot assessment of spatiotemporal distortions and can be adapted to assess high repetition-rate laser quality in HED experiments.

Simulations of wavelength-multiplexed holography for single-shot spatiotemporal characterization of NIF's advanced radiographic capability (ARC) laser.

We simulate the use of a newly developed single-shot wavelength-multiplexed holography-based diagnostic, STRIPED FISH, to fully characterize the as-delivered laser pulses of the National Ignition Facility's Advanced Radiographic Capability (NIF-ARC) laser. To that end, we have performed simulations of the NIF-ARC pulse incorporating (a) a time-integrated spatial-profile measurement and a complete temporal-intensity-and-phase measurement using a frequency resolved optical gating, but without any spatiotemporal pulse characterizations, and (b) simulated first-order spatiotemporal distortions, which could be measured on a single shot if a STRIPED FISH device were deployed.

HISTOPATOLOGI HATI IKAN PATIN YANG DIBERI PAKAN MENGANDUNG TEPUNG KUNYIT

This research was conducted from February to May 2019. The purpose of this study was to determine the network structure of striped catfish fed with turmeric flour before and after being tested with Aeromonas hydrophila. Sampling of histopathological preparations was carried out 2 times, namely at the beginning of maintenance, 30 days of maintenance and 14 days after the challenge test. The observed organ was the liver. The results of histological observations of catfish liver for 30 days of maintenance and fed with turmeric flour were still good. The structure of liver tissue after being challenged in treatment P1, P2 and P3 suffered damage such as hypertrophy, vacuole degeneration and necrosis. The best dose of adding turmeric flour to feed is 0.7 g / kg (P2) with the least damage.Key words: Striped fish, histopathology, liver, necrosis, turmeric flour

Complete measurement of spatiotemporally complex multi-spatial-mode ultrashort pulses from multimode optical fibers using delay-scanned wavelength-multiplexed holography.

We introduce a simple delay-scanned complete spatiotemporal intensity-and-phase measurement technique based on wavelength-multiplexed holography to characterize long, complex pulses in space and time. We demonstrate it using pulses emerging from multi-mode fiber. This technique extends the temporal range and spectral resolution of the single-frame STRIPED FISH technique without using an otherwise-required expensive ultranarrow-bandpass filter. With this technique, we measured the complete intensity and phase of up to ten fiber modes from a multi-mode fiber (normalized frequency V ≈10) over a ~3ps time range. Spatiotemporal complexities such as intermodal delay, modal dispersion, and material dispersion were also intuitively displayed by the retrieved results. Agreement between the reconstructed color movies and the monitored time-averaged spatial profiles confirms the validity to this delay-scanned STRIPED FISH method.

A single-frame full spatiotemporal field distribution measurement method

In this paper, based on the spatially and temporally resolved intensity and phase evaluation device: full information from a single hologram (STRIPED FISH), an improved single-frame full spatiotemporal field distribution measurement method is proposed. In our scheme, between diffractive optical element (DOE) and band-pass filter (BPF), and between BPF and the CCD camera, digital micromirror devices (DMD) are introduced to perfect the setup. Compared with the STRIPED FISH, our improved scheme can simultaneously improve the frame rate and maximize the utilization efficiency of the SBP of CCD. And simulation is carried out to demonstrate the process of the implementation, which confirmed the feasibility of the proposal.

Measurement of the ultrafast lighthouse effect using a complete spatiotemporal pulse-characterization technique

Three of the four spatiotemporal pulse amplitude couplings—spatial chirp, angular dispersion, and pulse-front tilt—are well known for their important roles in optics and, especially, in ultrafast optics. The remaining one, only recently identified, corresponds to the pulse arrival time variation with angle and is known as the “ultrafast lighthouse effect.” This effect has important applications in attosecond science, but its characterization has not yet received much attention. In this work, we generate an ultrafast lighthouse and measure it using a recently developed single-frame complete spatiotemporal pulse-characterization technique called STRIPED FISH. We discuss in great detail the measured couplings in different domains and their roles in generating the ultrafast lighthouse effect. In addition, we display the propagation of the measured ultrafast lighthouse with an intuitive movie plot over space and time. We conclude that STRIPED FISH provides a simple and informative approach for measuring the ultrafast lighthouse effect and also other possible spatiotemporal distortions in the pulse, in both the horizontal and vertical dimensions.

Numerical simulations of holographic spatiospectral traces of spatiotemporally distorted ultrashort laser pulses.

We simulate traces for a catalog of spatiotemporally complex pulses measured using a single-shot complete spatiotemporal pulse-measurement technique we recently developed, called Spatially and Temporally Resolved Intensity and Phase Evaluation Device: Full Information from a Single Hologram (STRIPED FISH). The only such technique ever developed to our knowledge, STRIPED FISH measures the complete spatiotemporal intensity I(x,y,t) and phase ϕ(x,y,t) of an arbitrary laser pulse using an experimentally recorded trace consisting of multiple digital holograms, one for each frequency present in the pulse. To understand the effects of various spatiotemporal distortions on the STRIPED FISH trace, we numerically investigate STRIPED FISH trace features for a catalog of pulses, including the spatially and temporally transform-limited pulse, temporal and spatial double pulses, spherically focusing and diverging pulses, self-phase modulated and self-focusing pulses, spatiotemporally coupled pulses, and pulses with complex structures. As a practical example, we also analyze an experimentally recorded trace of a focusing pulse with spatial chirp. Overall, we find that, from STRIPED FISH's informative trace, significant spatiotemporal characteristics of the unknown pulse can be immediately recognized from the camera frame. This, coupled with its simple pulse-retrieval algorithm, makes STRIPED FISH an excellent technique for measuring and monitoring ultrafast laser sources.

Complete characterization of a spatiotemporally complex pulse by an improved single-frame pulse-measurement technique

We further develop a simple device, called Spatially and Temporally Resolved Intensity and Phase Evaluation Device: Full Information from a Single Hologram (STRIPED FISH), for measuring the complete spatiotemporal intensity and phase, I(x,y,t) and ϕ(x,y,t), respectively, of an arbitrary ultrashort pulse on a single camera frame (and hence, on a single shot). We have increased the measurable bandwidth, eliminated most aberrations, and improved the uniformity of the multiple holograms in the device. We demonstrate these improvements by making single-camera-frame measurements of spatiotemporally complex subpicosecond crossed and chirped pulses from a Ti:sapphire oscillator. In order to display the massive resulting data files—pairs of four-dimensional intensity-and-phase data—we also develop a method for generating intuitive movies of the measured pulses. With these improvements, this device and its resulting movies should be able to perform and intuitively display true single-shot spatiotemporal measurements of most current ultrashort pulses.