應用場強增益之奈米結構於高階諧波之極紫外光系統開發與應用光導天線於兆赫波產生

Abstract

利用強場雷射激發惰性氣體的高階諧波產生法已經發展有段時間，本實驗希望利用具有表面電漿子之奈米結構增強電場強度，使之達到可以產生高階諧波的強度門檻，進而達到極紫外光波段，相較於以往使用頻脈衝放大技術於高階諧波產生極紫外光光源，更佳小型方便，我們製作了兩種場強增益的奈米結構與模擬，並架設了高階諧波光路系統，期望在未來可以應用在極紫外光微影與檢測。 另外，我們架設了兆赫波時域頻譜系統，利用飛秒雷射作為光源，光導天線作為發射端與接收端，量測到160皮秒的訊號。我們做了外加偏壓與雷射光強的訊號比較，發現場強跟偏壓及雷射光強的相依性。期望往後在生物檢測以及材料檢測上有幫助。

It has been long time for using intense laser targeting on noble gas to generate high harmonic generation (HHG). In our experiment, we expect that we can generate extreme ultraviolet (EUV) region by using nanostructures with surface plasmon to enhance laser electric field exceeding the threshold in HHG. Compared with chirped-pulse amplification generating HHG, our experimental setup is small-scale and convenient. We fabricated two nanostructures with field enhancement for HHG and simulated them, and set up HHG system. It is expected to applying EUV inspection or EUV lithography. Otherwise, we set up terahertz time domain spectroscopy (THz-TDS), using femtosecond laser as light source and using photoconductive antennas as emitter and receiver. We detected signals and the pulse duration is 160 ps. We compared the pulses with bias voltage and optical power, and the amplitude of radiation field depends on bias voltage and optical power. We expect to apply to bio-sensing and inspection of material in the future.