[en] Ray trace and filtered random phase can be used as initial phase to design continuous phase plates (CPPs). The performance of the CPPs designed with the two ways was studied. The results show that the CPP with filtered random phase as initial phase has better defocusing and amplitude aberration tolerance compared with that with ray trace as initial phase. What's more, wavefront aberration is the primary factor affecting the CPP'S performance and the tolerance to it is related with focal spot size. Thus relative phase aberration factor was introduced to quantify wavefront aberration and focal spot size and with the defined CPP performance standard the tolerance was 0.5 aberration factor. (authors)

[en] By comparing and analyzing various frequency conversion schemes, a compatible harmonic generation system has been designed. With type-Ⅱ-type-Ⅱ crystal combination configuration, polarization mismatch third harmonic generation and type-Ⅱ orthogonal quadrate second harmonic generation can be quickly switched. The thicknesses were optimized to be 10 mm for both crystals by numerical simulation method, as a result, the requirements of high efficiency for long pulse with low intensity, as well as high stability for short pulse with high intensity, can be satisfied. (authors)

[en] A 2ω wedge design is proposed with KDP crystal to disperse the unconverted light away from the target in a high power laser facility for inertial confinement fusion. The ultraviolet B-integral problem is released, and about 1.2 times in color separation angle is achieved according to both theoretical and experimental investigations when compared with conventional 3ω wedge. The frequency conversion efficiency is unaffected when the wedge is along the non-sensitive axis of the tripler. (authors)

[en] An analytic model for nonlinear propagation theory is developed for multi-wavelength laser beams propagating in an isotropic media. The small-scale self-focusing theoretical solution of multi-wavelength beams is obtained and is superposed by eigenfunctions with multiple local fastest-growth frequency, so the traditional B-integral obtained from a single-wavelength beam cannot be used to describe the small-scale self-focusing of multi-wavelength beams. Some laws for multi-wavelength beams propagating in an isotropy medium are also found, such as the self-focusing distance decreasing, the large angle scattering increasing and the spatial distributions of each wavelength trending to be consistent. The theoretical laws are confirmed by integrated numerical simulations and provide an explanation for the final optics phenomenon in high power lasers. The results promote the understanding of self-focusing theory and provide a very promising tool for beam control, which can transfer information from one beam to another through isotropic media. (paper)

[en] A method of designing continuous phase plates(CPP) for beam smoothing has been studied. The new CPP was obtained through adding some procedures into the traditional Gerchberg-Saxton(G-S) algorithm that was giving a new way of initial phase, adding steps of unwrapping and filtering in iterative procedure and aiming at controlling the spatial spectrum of focal spot. The surface of CPP was continuous and controllable, and compared to the traditional design, it could reduce the GRMS of CPP, get better focal spot shape, and depress the special frequency region's modulation. Combined with SSD, the new CPP have the better effect for controlling focal spot than the CPP designed by 'standard' method. (authors)

[en] Quantum light sources serve as one of the key elements in quantum photonic technologies. Such sources made from semiconductor material, e.g., quantum dots (QDs), are particularly appealing because of their great potential of scalability enabled by the modern planar nanofabrication technologies. So far, non-classic light sources based on semiconductor QDs are currently outperforming their counterparts using nonlinear optical process, for instance, parametric down conversion and four-wave mixing. To fully exploring the potential of semiconductor QDs, it is highly desirable to integrate QDs with a variety of photonic nanostructures for better device performance due to the improved light-matter interaction. Among different designs, the photonic nanostructures exhibiting broad operation spectral range is particularly interesting to overcome the QD spectral inhomogeneity and exciton fine structure splitting for the generations of single-photon and entangled photon pair respectively. In this review, we focus on recent progress on high-performance semiconductor quantum light sources that is achieved by integrating single QDs with a variety of broadband photonic nanostructures i.e. waveguide, lens and low-Q cavity. (reviews)