本論文利用 multiple-plate compression (MPC)的技術來產生中心波長在800奈米的高對比度單週期脈衝。在磊浦-探測實驗中需要高對比度的短脈衝來提升量測的解析度及準確性並且避免不必要的非線性效應產生。如今，傳統的脈衝清潔技術通常為人詬病於其轉換效率，特別是在寬頻的條件下。因此，我們通過利用兩級MPC的光譜再分配過程提出了一種新穎的高效率脈衝清潔技術，並且可以應用於數週期脈衝產生所需的超過一個八度的光譜範圍。
這個實驗由一個脈衝能量為160微焦耳、重複率為1千赫茲、脈衝寬度為34飛秒並且中心波長在800奈米的光源開始，我們將此光源聚焦進入第一階段的MPC系統中展頻，其產生出來的頻譜寬度為460奈米到960奈米並且具有125微焦耳的脈衝能量並對應到78.1%的轉換效率，接著我們利用一組頻寬有限的啁啾反射鏡組將此脈衝壓縮至3.51飛秒，但是由於頻譜形狀及不完美的壓縮，在脈衝兩側留下兩個分別為21% 及36%的旁辦。接著，具有 90微焦耳脈衝能量的脈衝被接續地聚焦進入第二階段的MPC系統中達成進一步的展頻及頻譜重塑。這個階段的輸出脈衝能量為82微焦耳且對應到高達91%的轉換效率，輸出的頻譜寬度為430奈米到1030奈米。接著有一小部分的光被送入脈衝整形器和空間相位調製器中進行相位補償，最後我們成功產生出2.62飛秒並伴隨著兩個11%旁辦的高對比度單週期脈衝。

In this thesis, we use the multiple-plate compression (MPC) system to generate high-contrast single-cycle pulses at central wavelength of 800 nm. In the pump-probe experiment, high-contrast short pulses are required to improve the resolution and accuracy of measurement and avoid unwanted nonlinear effects. Nowadays, conventional pulse cleaning techniques usually suffer from low efficiency, especially for a wide range of the spectrum. Hence, we propose a novel, high-efficiency pulse cleaning approach via spectral redistribution utilizing two-stage MPC, supporting more than one-octave spectrum for the few-cycle pulse generation.
The experiment begins from a light source with pulse energy of 160 μJ, repetition rate of 1 kHz, pulse duration of 34 fs and central wavelength of 800 nm, we focus the pulses into the quartz plates in first MPC stage for nonlinear broadening, the generated spectral bandwidth covers from 460 nm to 960 nm and the output energy is 125 μJ, corresponding to conversion efficiency of 78.1%. Then we use bandwidth-limited chirped mirrors compressor to compress the pulses down to 3.51 fs but remain two sidelobes with 21% and 36% respectively due to both the spectral shape and the imperfect compression. The compressed pulses with energy of 90 μJ are sequentially focused into the second MPC stage for the spectrum further broadening and reshaping. The output energy of this stage is 82 μJ, corresponding to conversion efficiency of up to 91.3%, and the output spectrum ranges from 430 nm to 1030 nm. Then a small portion of the light is sent into 4-f pulse shaper combined with a spatial light modulator to do phase compensation. Finally, we successfully generate 2.62 fs high-contrast single-cycle pulses where its two sidelobes are suppressed down to 11%.

摘要 i
Abstract ii
Acknowledgment iv
List of Figures vi
List of Tables ix
Chapter 1 Introduction 1
Chapter 2 Theory 4
2.1 Supercontinuum generation (SCG) 4
2.1.1 Optical Kerr effect 4
2.1.2 Self-focusing 5
2.1.3 Self-phase modulation (SPM) 6
2.1.4 Self-steepening 9
2.1.5 Multiple-plate compression (MPC) 11
2.2 Pulse compression 13
2.2.1 Chirped mirrors 13
2.2.2 4-f pulse shaper 14
2.2.3 Spatial light modulator (SLM) 16
2.3 Pulse cleaning 18
2.3.1 Nonlinear ellipse rotation (NER) 18
2.3.2 Cross polarization wave (XPW) generation 20
2.3.3 Plasma mirror (PM) 21
2.3.4 Filtered self-phase-modulation (SPM)-broadened spectrum 22
Chapter 3 Experiment 25
3.1 Light source and characterization 26
3.2 First MPC stage 27
3.2.1 Compression setup 29
3.2.2 Compression result 29
3.3 Second MPC stage 32
3.3.1 Parameter comparisons 32
3.3.2 Compression setup 41
3.3.3 Compression result 43
3.4 Pulse contrast enhancement 44
Conclusion and Prospect 47
Reference 48

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