Solution‐printed organic single‐crystalline films hold great potential for achieving low‐cost manufacturing of large‐area and flexible electronics. For practical applications, organic field‐effect transistor arrays must exhibit high performance and small device‐to‐device variation. However, scalable fabrication of highly aligned organic crystalline arrays is rather difficult due to the lack of control over the crystallographic orientation, crystal uniformity, and thickness. Here, a facile solution‐printing method to fabricate centimeter‐sized highly aligned organic crystalline arrays with a thickness of a few molecular layers is reported. In this study, the solution shearing technique is used to produce large‐area, organic highly crystalline thin films. Water‐soluble ink is printed on the hydrophobic surface of organic crystalline films, to selectively protect it, followed by etching. It is shown that the addition of a surfactant dramatically changes the fluid drying dynamics and increases the contact line friction of the aqueous solution to the underlying nonwetting organic crystalline film. As a result, centimeter‐scale highly aligned organic crystalline arrays are successfully prepared on different substrates. The devices based on organic crystalline arrays show good performance and uniformity. This study demonstrates that solution printing is close to industrial application and also expands its applicability to various printed flexible electronics.

We demonstrate the first achievement of continuous-wave (CW) pumped second harmonic generation (SHG) in few- and mono-layer gallium selenide (GaSe) flakes, which are coated on silicon photonic crystal (PC) cavities. Because of ultrahigh second order nonlinearity of the two-dimensional (2D) GaSe and localized resonant mode in the PC cavity, SHG’s pump power is greatly reduced to microwatts. In a nine-layer GaSe coated PC cavity, while the optical power inside the GaSe flake is only 1.5% of that in the silicon PC slab, the SHG in GaSe is more than 650 times stronger than the third harmonic generation in silicon slab, indicating 2D GaSe’s great potentials to strengthen nonlinear processes in silicon photonics. Our study opens up a new view to expand 2D materials’ optoelectronic applications in nonlinear regime and chip-integrated active devices.

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By using spectrally noncritical phase-matching in a partially deuterated KDP around its retracing point of phase-matching, we have experimentally and numerically investigated the characteristics of second-harmonic generation (SHG) with femtosecond laser at 1 microm for the first time. This phase-matching configuration can support efficient SHG over 20nm bandwidth of the fundamental laser at 1 microm in a 10-mm-long crystal. Efficiency of harmonic conversion as high as 55% has been demonstrated.

We demonstrated a ultra-stable pulse based on the high-quality electrochemical delamination exfoliation process black phosphorus.

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With the upgrade program of SG-II laser facility, 1kJ PW laser system based on its Nd:glass ninth beam has been designed for the scientific research on high energy density physics, ICF, especially the fast ignition. In this paper the design overview is presented. According to the schedule, the installation of optics and mechanics will be finished by the middle of 2009, and the operation will start in half year later.