Abstract. Background: The benefits of microresonator lasers include easy and low-cost fabrication methods and high-quality factor of microresonators, which results in low threshold current of the fabricated laser. However, the lack of tunable fabrication methods with precise size and spacing is a great challenge. Aim: Based on a microsphere fabrication method that relies on injection and surface tension effects, simultaneous demonstration of an array of cavities with precise spacing and sizes is possible where the size of cavities is widely tunable. Approach: Using a maskless lithography setup, pillars with base and tip diameters of 250 and 60μm are fabricated, which are used for demonstration of microspheres with tunable size, depending on the applied pump pressure. Microcavities composed of Rhodamine B dissolved in glycerol are injected into the polydimethylsiloxane carrier through a nozzle with a diameter of 70  μm. Results: An ∼4-μJ  /  mm2 lasing threshold has been obtained for a laser with a microsphere diameter of ∼350  μm. A redshift originated from the increment of dye concentration has also been observed. Conclusions: Fabrication of precise microspheres for a microresonator laser is feasible using the introduced method, which can be further generalized using different active materials.

中文翻译：

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基于精确成型的染料掺杂微球腔的可调谐微激光器

摘要。背景：微谐振器激光器的优点包括简单且低成本的制造方法和微谐振器的高品质因数，这导致制造的激光器的阈值电流低。然而，缺乏具有精确尺寸和间距的可调制造方法是一个巨大的挑战。目标：基于依赖于注射和表面张力效应的微球制造方法，可以同时演示具有精确间距和尺寸的空腔阵列，其中空腔尺寸可广泛调节。方法：使用无掩模光刻装置，制造底部和尖端直径分别为 250 和 60μm 的柱，用于演示具有可调尺寸的微球，具体取决于施加的泵压力。由溶解在甘油中的罗丹明 B 组成的微腔通过直径为 70 μm 的喷嘴注入聚二甲基硅氧烷载体中。结果：微球直径为 ∼350 μm 的激光器获得了 ∼4-μJ / mm2 的激光阈值。还观察到源自染料浓度增加的红移。结论：使用所介绍的方法制造用于微谐振器激光器的精确微球是可行的，并且可以使用不同的活性材料进一步推广。