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.

题目：新型大功率紫外激光器技术描述：该项目的目标是通过四次谐波产生开发超快、深紫外（UV）激光源。改进的t腔垂直外腔面发射激光器（VECSEL）工作在240-260nm范围内，脉冲宽度为10ps，峰值功率为10W。提出的设计将消除对昂贵和低效的腔稳定电子器件的需求，并将推动各个领域的界限，包括：非线性光学，半导体激光器，腔设计和超快脉冲产生。作为研究的一部分，将设计和发展一种新的VECSEL增益材料，以提供短脉冲产生所需的大增益带宽，同时仍然提供高峰值功率。这种新的增益材料与t型腔结构的半导体吸收镜相结合，将允许开发一种新的激光源，可以使科学，医学，材料加工和工程研究的未来进步。此外，该研究小组将通过REU项目和本科研究为来自代表性不足群体的个人提供出色的研究经验。每年有两名本科生参加暑期和/或学术实习。技术描述：提出的研究将实现一种新的t型腔结构，用于四次谐波的产生，并消除对腔稳定电子设备的需求。通常情况下，第四次谐波产生的紫外线使用一个源激光，耦合到一系列的外部谐振腔，再循环的基本和二次谐波模式。这些外腔对微小的运动非常敏感，这些运动会导致光束的相位变化和紫外线输出的大功率波动。这种情况要求每个腔都有其谐振锁定，以确保稳定的输出。这类系统庞大、复杂且昂贵，限制了它们在实验室环境之外的潜在应用。由于设计的全内部性质，拟议的研究将消除外部腔的需要。在这里，基场的频率在非线性光学（NLO）晶体中翻倍，以产生二次谐波。当倍频场与基频正交极化时，腔内偏振分束器将该场驱逐到交替的腔路中。虽然这不是一个谐振腔，但将光注入外部谐振腔的困难被消除了。二次谐波在腔内产生，并产生一个大的场，在这个场中，另一个NLO晶体可以有效地将这个场的频率翻倍到紫外线。虽然稳定电子设备可以改善腔内的场积累，但研究的重点是在没有额外元件的情况下获得稳定的峰值功率输出。

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