本文首先通过磁控溅射技术在单晶Si和Al2O3陶瓷衬底上分别依次沉积厚度为600 nm的Cu和Cu55Ni45薄膜，然后使用微加工技术在10 mm×10 mm的衬底区域内制备了200对串联的热电偶组成薄膜热电堆结构，最后采用反应溅射联合硬掩膜沉积了不同厚度的氧化铝热阻层，使串联的热电偶分别产生冷端和热端。根据Seebeck效应，在热流的作用下薄膜热电堆冷热两端的温差使传感器输出热电信号，实现对热流密度的测量。通过对薄膜热电堆的表征与标定，结果表明：沉积在Si衬底与Al2O3陶瓷衬底上的Cu/Cu55Ni45热电堆中，Cu膜粗糙度分别为20和60 nm，Cu55Ni45膜粗糙度分别为15和20 nm，电阻分别为38.2 Ω和2.83 kΩ，灵敏度分别为0.069 45和0.026 97 mV/(kW·m-2)。具有不同表面粗糙度的单晶Si衬底与Al2O3陶瓷衬底会影响在其表面沉积的Cu/Cu55Ni45热电堆表面粗糙度，进而导致薄膜热电堆产生电阻大小差异，此外，Cu/Cu55Ni45热流传感器的输出热电势与热流密度呈现良好的线性关系。

介绍了一种通过单层光学介电微球阵列对激光进行调制进而对微球表面的金膜进行加工的工艺方法，采用该方法可以高速地对大面积微球阵列上的金膜进行微米量级分辨率的图案化加工。针对介电微球阵列通过光学近场实现突破衍射极限的聚光进行了分析，然后采用软件模拟了微球对光场的调控，讨论了微球直径以及激光波长对加工精度的影响。通过改变工艺参数，分别研究了激光波长、介电微球直径、离子溅射镀膜厚度及激光照射的能量密度对加工出的金微纳结构的影响，得到了最佳的加工工艺参数。在此最佳工艺条件下能加工出直径约为100 nm的金膜单孔洞结构。通过改变激光的入射角度，研究了适合图案化加工的步进和线宽，最终加工出了线宽为280 nm的简单图案。

Liquid-assisted laser ablation has the advantage of relieving thermal effects of common laser ablation processes, whereas the light scattering and shielding effects by laser-induced cavitation bubbles, suspended debris, and turbulent liquid flow generally deteriorate laser beam transmission stability, leading to low energy efficiency and poor surface quality. Here, we report that a continuous and directional high-speed microjet will form in the laser ablation zone if laser-induced primary cavitation bubbles asymmetrically collapse sequentially near the air-liquid interface under a critical thin liquid layer. The laser-induced microjet can instantaneously and directionally remove secondary bubbles and ablation debris around the laser ablation region, and thus a very stable material removal process can be obtained. The shadowgraphs of high-speed camera reveal that the average speed of laser-induced continuous microjet can be as high as 1.1 m s-1 in its initial 500 μm displacement. The coupling effect of laser ablation, mechanical impact along with the collapse of cavitation bubbles and flushing of high-speed microjet helps achieve a high material removal rate and significantly improved surface quality. We name this uncovered liquid-assisted laser ablation process as laser-induced microjet-assisted ablation (LIMJAA) based on its unique characteristics. High-quality microgrooves with a large depth-to-width ratio of 5.2 are obtained by LIMJAA with a single-pass laser scanning process in our experiments. LIMJAA is capable of machining various types of difficult-to-process materials with high-quality arrays of micro-channels, square and circle microscale through-holes. The results and disclosed mechanisms in our work provide a deep understanding of the role of laser-induced microjet in improving the processing quality of liquid-assisted laser micromachining.

Ultrashort laser pulses confine material processing to the laser-irradiated area by suppressing heat diffusion, resulting in precise ablation in diverse materials. However, challenges occur when high speed material removal and higher ablation efficiencies are required. Ultrafast burst mode laser ablation has been proposed as a successful method to overcome these limitations. Following this approach, we studied the influence of combining GHz bursts in MHz bursts, known as BiBurst mode, on ablation efficiency of silicon. BiBurst mode used in this study consists of multiple bursts happening at a repetition rate of 64 MHz, each of which contains multiple pulses with a repetition rate of 5 GHz. The obtained results show differences between BiBurst mode and conventional single pulse mode laser ablation, with a remarkable increase in ablation efficiency for the BiBurst mode, which under optimal conditions can ablate a volume 4.5 times larger than the single pulse mode ablation while delivering the same total energy in the process.