Ultrafast deep UV laser source by all intracavity fourth harmonic generation

全腔内四次谐波产生的超快深紫外激光源

• 批准号: 1709918
• 负责人: Chris Hessenius
• 金额: $ 37.84万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-05-01 至 2020-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1709918&HistoricalAwards=false
• 关键词: Ultrafast; deep; UV; laser; source

Title: Novel High-Power, Ultra-Violet LasersNon-Technical Description:The goal of this project is to develop an ultrafast, deep ultra-violet (UV) laser source by fourth harmonic generation. A modified t-cavity vertical external cavity surface emitting laser (VECSEL) is to operate in the 240-260nm range with pulse widths 10ps and peak powers 10W. The proposed design will eliminate the need for expensive and inefficient cavity stabilization electronics and will push the boundaries in various fields including: nonlinear optics, semiconductor lasers, cavity design, and ultrafast pulse generation. As part of the research, a new VECSEL gain material will be designed and grown to deliver the large gain bandwidth needed for short pulse generation while still providing high peak powers. This new gain material combined with a semiconductor absorber mirror in a t-cavity configuration will allow development of a new laser source that can enable future advancements in science, medicine, material processing, and engineering research. In addition, this research group will provide an excellent research experience for individuals from under-represented groups through REU programs and undergraduate research. Two undergraduate students are to be involved each year for summer and/or academic internship. Technical Description:The proposed research will implement a novel t-cavity configuration for fourth harmonic generation and eliminate the need for cavity stabilization electronics. Typically, fourth harmonic generation to the UV uses a source laser that is coupled into a series of external resonator cavities that recirculate the fundamental and second harmonic modes. These external cavities are very sensitive to minor movements which lead to phase variations of the beams and to large power fluctuations of the UV output. This situation requires that each cavity have their resonances locked to ensure stable outputs. Such systems are large, complicated, and expensive which limits their potential use outside of a laboratory environment. The proposed research will eliminate the need of the external cavity due to the all-internal nature of the design. Here, the fundamental field is frequency doubled in a nonlinear optical (NLO) crystal for second harmonic generation. As the frequency doubled field is orthogonally polarized to the fundamental, an intra-cavity polarizing beam splitter expels this field into an alternate cavity path. While this is not a resonant cavity, the difficulty of injecting the light into an external resonator is eliminated. The second harmonic is generated inside this cavity and creates a large field in which another NLO crystal can efficiently frequency double this field to the UV. While stabilization electronics would improve the field build-up in the cavity, the research is focused on obtaining a stable high peak power output without additional elements.

标题：新颖的高功率，超紫色的激光技术描述：该项目的目的是通过第四次谐波生成开发超快的深层超紫罗莱氏（UV）激光源。修改的T-cavity垂直外部空腔表面发射激光器（VECSEL）将在240-260nm范围内运行，脉冲宽度10PS和峰值功率为10W。拟议的设计将消除对昂贵且效率低下的腔稳定电子产品的需求，并将在各个领域的界限上推动界限，包括：非线性光学元件，半导体激光器，腔设计和超快脉冲产生。作为研究的一部分，将设计和生长一种新的VECSEL增益材料，以提供短脉冲产生所需的大增益带宽，同时仍提供高峰值功率。这种新的增益材料与T-cavity配置中的半导体吸收器镜相结合，将允许开发新的激光源，该源可以在科学，医学，材料处理和工程研究方面取得进步。此外，该研究小组将通过REU计划和本科研究为来自代表性不足小组的个人提供出色的研究经验。夏季和/或学术实习，每年将参与两名本科生。 技术描述：拟议的研究将实施一种新型的T型腔配置，以进行第四次谐波生成，并消除对腔稳定电子产品的需求。通常，紫外线的第四个谐波生成使用源激光器，该激光器与一系列外部谐振器腔耦合，这些射量循环了基本和第二个谐波模式。这些外部空腔对次要运动非常敏感，这会导致梁的相变和紫外线输出的大功率波动。这种情况要求每个腔都锁定了共振，以确保稳定的输出。这样的系统是大型，复杂且昂贵的，这限制了它们在实验室环境之外的潜在使用。拟议的研究将由于设计的跨内部性质而消除外部空腔的需求。在这里，基本场在第二次谐波生成的非线性光学（NLO）晶体中频率加倍。由于频率的频率两倍是正交极化与基本的两极化，因此腔内极化束分离器将该场排出到替代空腔路径中。尽管这不是谐振腔，但消除了将光注射到外部谐振器中的困难。第二个谐波是在该腔内生成的，并创建了一个大磁场，其中另一个NLO晶体可以有效地将此磁场频率加倍到UV。虽然稳定电子设备将改善腔体的田间积累，但该研究的重点是获得稳定的高峰值输出，而无需其他元素。

项目成果

High peak power, sub-ps green emission in a passively mode locked W-cavity VECSEL

被动锁模 W 腔 VECSEL 中的高峰值功率、亚 ps 绿色发射

• DOI: 10.1364/oe.384439
• 发表时间: 2020
• 期刊: Optics Express
• 影响因子: 3.8
• 作者: Meyer, Jason T.;Lukowski, Michal L.;Hessenius, Chris;Wright, Ewan M.;Fallahi, Mahmoud
• 通讯作者: Fallahi, Mahmoud