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Cheng K.,China Institute of Technology | Zhang S.,China Institute of Technology | Li W.,China Institute of Technology | Dai W.,Laser Fusion Research Center | And 2 more authors.
Chinese Optics Letters | Year: 2015

In this Letter, temporal self-modifying behavior of amplitude modulation pulse propagation characteristics in multiphoton absorbers is presented by solving the underlying theoretical model coupling the propagation equation with the rate equations. The characteristics of the output temporal shapes are of primary concern and are discussed in detail. Amplitude modulation suppressing effects of multiphoton absorbers are numerically demonstrated; they have not been reported previously, to our knowledge. By taking a time resolved absorption coefficients, the corresponding physical mechanism is explicitly interpreted. © 2015 Chinese Optics Letters.

Cui Y.,Shanghai Institute of Laser Plasma | Gao Y.,Shanghai Institute of Laser Plasma | Gao Y.,Shanghai JiaoTong University | Zhao Z.,Shanghai Institute of Laser Plasma | And 11 more authors.
IEEE Photonics Technology Letters | Year: 2016

An attosecond precision and femtosecond range timing jitter measurement and control technique is proposed. It is based on the modulation of the combined pulse induced by relative time delay of individual pulses. The core of this timing jitter detection method is the integrated technique of optical cross correlation and electrical energy interferometry. To illustrate this technique, a proof-of-principle experiment is demonstrated based on two 237 fs pulses. The peak-to-valley timing jitter of the two pulses to be combined is less than 700 as in 1 h and the average efficiency of coherent beam combining could reach to 91.6%. © 1989-2012 IEEE.

Han J.,No. 29 Jiuyanqiao Wangjiang Road | Li Y.,Fine Optical Engineering Research Center | Zhang Q.,No. 29 Jiuyanqiao Wangjiang Road | Fu Y.,No. 29 Jiuyanqiao Wangjiang Road | And 6 more authors.
Applied Surface Science | Year: 2010

The characteristics and mechanisms of the damage to absorbing glass with high-repetition laser pulses (several kHz) are discussed. The results show that: (1) in the range of comparatively low-repetition rate, the damage is characterized by material melting and a small crater on the surface of substrate; (2) with the increase in repetition rate, a bigger and deeper crater is surrounded by re-deposition and crystalline granules originating from the cooling of vapor; and (3) the crater, surrounded by evaporation and an large number of solid particulates which is obviously the characters of phase explosion, becomes even bigger and deeper when the repetition rate is further increased. We modeled the temperature distribution in different repetition rate regime and found that heat accumulation plays a significant role in damage process. Because of the temperature dependence of damage mechanism, the temperature of the area irradiated by laser beam will ramp up with increasing the repetition rate, which triggers the melting and evaporation of dielectrics and phase explosion successively. Our results may benefit the understanding of laser-induced damage in optical materials. © 2010 Elsevier B.V.

Dong Y.,Laser Fusion Research Center | Yang J.,Laser Fusion Research Center | Song T.,Laser Fusion Research Center | Zhu T.,Laser Fusion Research Center | Huang C.,Laser Fusion Research Center
Plasma Science and Technology | Year: 2016

As a fundamental and crucial research topic in the direct-driven inertial confinement fusion (ICF), especially for shock ignition (SI), investigation on the laser coupling with planar low-Z targets is beneficial for deep physical comprehension at the primary phase of SI. The production of the intense shock and the shock coalescence in the multi-layer targets, driven by the 3ω intense laser (351 nm the wavelength), were studied in detail with the 1D and 2D radiation hydrodynamic simulations. It was inferred that the 1D simulation would overrate the shock velocity and the ablation pressure of the spike; the coalescence time and the velocity of the coalescence shock depended evidently on the pulse shape and the start time of the spike. The present study can also provide a semi-quantitative reference for the design of the SI decomposition experiments on the Shenguang-III prototype laser facility.

Song T.,Laser Fusion Research Center | Yang J.,Laser Fusion Research Center | Zhu T.,Laser Fusion Research Center | Li Z.,Laser Fusion Research Center | Huang C.,Laser Fusion Research Center
Plasma Science and Technology | Year: 2016

An experiment was performed on the Shenguang III prototype laser facility to continue the study on hohlraum radiation source with approximately constant radiation temperature using a continuously shaped laser pulse. A radiation source with a flattop temperature of about 130 eV that lasted about 5 ns was obtained. The previous analytical iteration method based on power balance and self-similar solution of ablation was modified taking into account the plasma movements and it was used to design the laser pulse shape for experiment. A comparison between experimental results and simulation is presented and better agreement was achieved using the modified method. Further improvements are discussed.

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