Neutron Imaging System (NIS) has been used to image the burn volume and cold fuel volume of imploding fusion capsules. In this work, we present a design of neutron imaging aperture for inertial confinement fusion in Laser Fusion Research Center. Since the total neutron yield should be less than 1014, the penumbral aperture has been chosen. A geometric model has been developed to assess the performance of the neutron imaging system, including the spatial resolution, the field of view and the signal-to-noise ratio. This model reproduces the performances of neutron image systems on OMEGA. The spatial resolution of designed NIS is about 22 μm for a field of view of 250 μm. The signal-to-noise ratio can be better than 10, if the neutron yield is higher than 1013.

Multilayer film structure is designed for hohlraum used in inertial confinement fusion. It is similar to low density foam material but easier to be fabricated and more flexible to change its equivalent density. Simulations and experiment of laser ablated planar targets reveal that, compared with solid gold, plasma expansion of multilayer gold films is mitigated and the x-ray flux is increased. The laser spot moves inwards and its speed can be controlled by adjusting the gaps between films.

We demonstrate an all-PM Er-doped soliton mode-locked fiber oscillator based on the figure-9 configuration with a compact adjustable reflection-type non-reciprocal phase shifter. An analytical model based on the Jones matrix is established to simulate the wavelength tuning phenomenon. Experimentally, it is observed that the increase in pump power results in a significant redshift in the spectrum of output pulses. When the angle of the half-wave plate is rotated in one direction, the output spectrum is redshifted and then blueshifted successively. Good qualitative agreement is presented between the simulations and the experimental results. It is shown that the increase in pump power changes the nonlinear phase shift, which causes the redshift of the transmittance curves at the laser output port. In contrast, the rotation of wave plates not only changes the nonlinear phase shift difference, but also causes variations in linear phase bias and modulation depth. The changes in these parameters lead to the redshift and blueshift of the transmission curves, which enables wavelength tuning.

Broadband low-coherence light is considered to be an effective way to suppress laser plasma instability. Recent studies have demonstrated the ability of low-coherence laser facilities to reduce back-scattering during beam–target coupling. However, to ensure simultaneous low coherence and high energy, complex spectral modulation methods and amplification routes have to be adopted. In this work, we propose the use of a random fiber laser (RFL) as the seed source. The spectral features of this RFL can be carefully tailored to provide a good match with the gain characteristics of the laser amplification medium, thus enabling efficient amplification while maintaining low coherence. First, a theoretical model is constructed to give a comprehensive description of the output characteristics of the spectrum-tailored RFL, after which the designed RFL is experimentally realized as a seed source. Through precise pulse shaping and efficient regenerative amplification, a shaped random laser pulse output of 28 mJ is obtained, which is the first random laser system with megawatt-class peak power that is able to achieve low coherence and efficient spectrum-conformal regenerative amplification.

Fast neutron radiography (FNR) using divergent neutron beams has the characteristic to magnify small cracks in low-Z materials. For such magnifying FNR systems, a simple method was developed using Monte Carlo simulations to estimate the spatial resolution. The resolution degrading factors, including neutron source size, object thickness, and crosstalk in the detector, have been investigated in this method. The calculated results of this method compare favorably to independent estimations of various designs for the same FNR system. For a magnifying FNR system, a better spatial resolution can be expected with larger magnifications and smaller sources.