为了满足荧光显微镜技术对多波长单模耦合输出激光的需求，研究了400~680 nm内多波长激光耦合进单模光纤的技术，设计了三片式耦合透镜组很好地消除了不同波长耦合时的色差以提高耦合效率，同时考虑光纤耦合调试难度大的问题，设计了能快速简单完成耦合调节的耦合光纤部件结构以及耦合调试的方法，通过实验测试荧光成像常用的4种波段激光（405，488，561，638 nm），耦合效率均大于65%。实验结果达到了较高的光纤耦合水平，证明该多波长激光耦合器性能优异。同时，由于耦合器装调简单且成本低，本文的工作具有进一步商业化的价值，且为多波长单模耦合激光器国产化打下了坚实的基础。

Impact and torsion pendulums are applied in impulse coupling experiments of high-energy laser irradiation of space debris. It is difficult to achieve a multi-pulse experiment and thus hard to analyze the multi-pulse impulse coupling effect. Here, we designed a new recoil impulse experimental measurement system of non-contact, multi-degrees of freedom, and multi-pulse irradiation. The system used a low-pressure and low-temperature vacuum chamber to simulate the space environment, the pinning effect of magnetic levitation to achieve aluminum target suspension, and high-speed cameras to record the displacement over time to calculate the impulse of the target. Then the impulse coupling experiment of multi-pulse laser irradiation on the aluminum target was performed. The result shows that the multi-pulse impulse coupling effect is not the linear accumulation of coupling results by every single-pulse and multi-pulse coefficient that decreases with the increase of the number of pulses, and eventually stabilizes as the decrease gets smaller.

Power scaling in a broad area quantum cascade laser (QCL) tends to deteriorate beam quality with the emission of a multiple-lobe far-field pattern. In this paper, we demonstrate a coupled ridge waveguide QCL array consisting of five elements with chirped geometry. In-phase mode operation is secured by managing supermode loss with properly designed geometries of ridges. A single-lobe lateral far-field with a near diffraction limited beam pattern was obtained in the whole current dynamic range. The devices were fabricated with the wet and dry etching method. The regrowth technique of the InP:Fe insulation layer and InP:Si waveguide layer was employed. Such a structure has the potential to optimize the beam quality of the recently reported high-power broad-area QCL with a reduced cascade number.

A novel method for converting an array of out-of-phase lasers into one of in-phase lasers that can be tightly focused is presented. The method exploits second-harmonic generation and can be adapted for different laser arrays geometries. Experimental and calculated results, presented for negatively coupled lasers formed in a square, honeycomb, and triangular geometries are in good agreement.