193- nm DUV laser produced by cascaded LBO crystals. Credit: H. Xuan (GBA branch of Aerospace Information Research Institute, Chinese Academy of Sciences), modified
Researchers established a 60- milliwatt solid-state DUV laser at 193 nm utilizing LBO crystals, setting brand-new criteria in effectiveness worths.
In the world of science and innovation, utilizing meaningful source of lights in the deep ultraviolet (DUV) area holds enormous significance throughout numerous applications such as lithography, problem evaluation, metrology, and spectroscopy. Traditionally, high-power 193- nanometer (nm) lasers have actually been critical in lithography, forming an important part of systems utilized for accurate pattern. However, the coherence restrictions connected with standard ArF excimer lasers prevent their efficiency in applications needing high-resolution patterns, like disturbance lithography.
Hybrid ArF Excimer Laser Technology
Enter the idea of the “hybrid ArF excimer laser.” Integrating a narrow linewidth solid-state 193- nm laser seed in location of the ArF oscillator attains boosted coherence together with narrow linewidth, hence allowing enhanced efficiency in high-throughput disturbance lithography. This development not just enhances pattern accuracy however likewise speeds up lithography speed.
Moreover, the hybrid ArF excimer laser’s increased < period class =(************************************** )aria-describedby ="tt" data-cmtooltip ="<div class=glossaryItemTitle>photon</div><div class=glossaryItemBody>A photon is a particle of light. It is the basic unit of light and other electromagnetic radiation, and is responsible for the electromagnetic force, one of the four fundamental forces of nature. Photons have no mass, but they do have energy and momentum. They travel at the speed of light in a vacuum, and can have different wavelengths, which correspond to different colors of light. Photons can also have different energies, which correspond to different frequencies of light.</div>" data-gt-translate-attributes="(** )" tabindex ="0" function ="link" > photon energy and coherence assist in direct processing of numerous products, consisting of carbon substances and solids, with very little thermal effect.This flexibility highlights its capacity in varied fields, from lithography to laser machining.
Advances inSolid-State DUVLaserGeneration
(*********************************************************************** )enhance seeding for an ArF amplifier, the linewidth of the193 -nm seed laser should be diligently managed, preferably listed below 4 ghz (GHz). This spec determines the coherence length essential for disturbance, a requirement easily fulfilled through solid-state laser innovations.
A current development from scientists at the Chinese Academy of Sciences moves this field forward. As reported in Advanced Photonics Nexus, they attained an exceptional 60- milliwatt (mW) solid-state DUV laser at 193 nm with a narrow linewidth utilizing an advanced two-stage amount frequency generation procedure using LBO crystals. The procedure includes pump lasers at 258 and 1553 nm, stemmed from a Yb- hybrid laser and an Er- doped fiber laser, respectively. This setup, culminating in a 2mm × 2mm ×30 mm Yb: YAG bulk crystal for power scaling, shows excellent outcomes.
The produced DUV laser, accompanied by its 221- nm equivalent, shows a typical power of 60 mW, a pulse period of 4.6 nanoseconds (ns), and a repeating rate of 6 kilohertz (kHz), with a linewidth of around 640 megahertz (MHz). Notably, this marks the greatest power output for both 193- and 221- nm lasers produced by an LBO crystal, in addition to the narrowest linewidth reported for a 193- nm laser.
Of specific note is the exceptional conversion effectiveness attained: 27 percent for 221 to 193 nm and 3 percent for 258 to 193 nm, setting brand-new criteria in effectiveness worths. This research study highlights the enormous capacity of LBO crystals in producing DUV lasers at power levels varying from numerous milliwatts to watts, opening opportunities for checking out other DUV laser wavelengths.
According toProf Hongwen Xuan, matching author for the work, the reported research study shows “the viability of pumping LBO with solid-state lasers for reliable and effective generation of narrow-linewidth laser at 193 nm, and opens a new way to fabricate a cost-effective, high-power DUV laser system using LBO.”
These improvements not just press the borders of DUV laser innovation however likewise hold guarantee for changing myriad applications throughout clinical and commercial domains.
Reference: “High-power, narrow linewidth solid-state deep ultraviolet laser generation at 193 nm by frequency mixing in LBO crystals” by Zhitao Zhang, Hanghang Yu, Sheng Chen, Zheng Li, Xiaobo Heng and Hongwen Xuan, 28 March 2024, Advanced Photonics Nexus
DOI: 10.1117/ 1. APN.3.2.026012
