Ar-Xe plasma laser and microplasma propagation

Ar-Xe laser;Microplasma

Zhong, Shengyuan ; Eden ; James Gary

关键词: Ar-Xe laser;    Microplasma;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/89095/ZHONG-THESIS-2015.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

The thesis consists of two parts. In the first part, we report on the development of Ar-Xe plasma in a SU-8 based microchannel structure which is suitable for on-chip gain medium for near-IR lasing at 823 nm wavelength. SU-8 microchannels with length varying from 1 cm to 5 cm and cross-section area of 100×100 µm were fabricated on silicon wafer using cleanroom fabrication technique. Microchannels were bounded by two up and down Au electrodes facing each other and a dielectric barrier discharge (DBD) structure was deployed for Ar-Xe plasma discharge. Stable plasma discharge was obtained from the device with Ar, Ne, Ar-Xe, He gases at voltages consistently below 1200 V. An intensified charge couple device (ICCD) was used to study the emission beam profile at the end of the microchannel. The spectrum of the emission on the channel end was taken to analyze the targeted wavelength 823 nm. Our study shows that the emission intensity at 823 nm wavelength increases exponentially at voltages higher than 700 V with 800 Torr and 4.5% Ar-Xe gas mixture. We still lack proof, but the amplified spontaneous emission (ASE) we tested on our Ar-Xe microchannel plasma device could potentially enable an on-chip near-IR to IR laser source, which would be very useful in future applications.In the second part of this thesis, we report on our study of the microplasma propagation phenomenon in our microchannel-cavity array device. We carried out multiple experiments to test different factors which affect microplasma propagation speed and pattern. Our tests showed that device geometry, nearby plasma condition, and injected power are three main factors influencing the propagation pattern and speed. With consideration of the above factors, we designed a microcavity-channel structure which can be used to control plasma discharge location by manipulating the nearby conditions. Our ICCD images show that the center plasma spot was moved successfully according to our ignition of the plasma in the nearby cavities. This result indicates a potential method to control plasma propagation in the future.