本論文採用multiple-plates continuum(MPC)的方式來產生一個中心波長在1030奈米的單一周期脈衝.本實驗的輸入光源來自於一台摻鐿鎢酸釓鉀(Yb-KGW)脈衝雷射。此雷射因為其高重複率和高平均功率而在如今被廣泛使用。然而，摻鐿鎢酸釓雷射的缺點在於其窄頻寬將最短脈衝寬度限制在幾百個飛秒。這將導致我們很難透過單一階段的MPC展頻將脈衝頻譜擴展到超過一個八度，得到一個單一周期脈衝。因此，我們建立兩階段的MPC展頻以及壓縮系統來幫助我們達成這個目標 。
在實驗的一開始，我們將一個具有1.07毫焦耳、1千赫茲、170飛秒、中心波長在1030奈米的輸入脈衝聚焦進第一階段的MPC中進行展頻。在經過展頻之後，輸出脈衝具有960奈米到1100奈米的頻寬範圍(底點到底點)，並且保留675微焦耳的能量。接著，我們將脈衝送進一套傅立葉整形器中來補償該脈衝的色散。在經過此套壓縮系統之後，脈衝具有29飛秒的時間寬度和275微焦耳的能量。此時，因為壓縮脈衝的尖峰功率高於初始尖峰功率的1.5倍，我們可以將其聚焦進第二階段的MPC中並進行在一次的展頻。在經過第二階段的展頻之後，輸出脈衝具有150微焦耳的能量以及超過一個八度(580奈米到1300奈米)的頻寬範圍。之後，藉由第二套的套傅立葉整形器，我們成功的得到一個具有50微焦耳能量、3.13飛秒脈衝寬度的單一周期脈衝。

In this thesis, we use the multiple-plates continuum (MPC) [1] method to generate one-cycle pulses at the central wavelength of 1030nm. In the experiment, the input light source come from the Yb-KGW commercial laser system, which is widely used because of its high repetition rate and high average power. However, the drawback of the Yb-KGW laser is its narrow bandwidth which limits the initial pulse duration to hundreds of femtoseconds. It is difficult to span the bandwidth over one octave to get one-cycle pulses. Thus, we build a two-stage MPC, together with the compressor system to achieve ultrashort pulses down to 3 fs.
In the beginning of the experiment, a 1.07 mJ, 1 kHz, 170 fs, 1030 nm input pulse was focused into the first MPC stage to span the input spectrum, the output pulse bandwidth (end-to-end) ranges from 960 nm to 1100 nm while the output energy is 675 μJ. Then, we send this pulses into the Fourier pulse shaper to compensate the dispersion. The pulse has compressed down to 29 fs, while the output energy is 275 μJ. It is interesting that the peak power of the compressed pulse is 1.5 times higher than the initial one and it is enough to do the second MPC broadening. Focused second MPC, the output pulse has 150uJ energy and a spectrum cover more than one octave from 580nm to 1300 nm at the -20 dB level. The second Fourier shaper was also utilized to deal with the dispersion compensation. Finally, we successfully obtain a 50 μJ, 3.13 fs one-cycle pulses.

[1] Chih-Hsuan Lu, et al. “Generation of intense supercontinuum in condensed media.” Optica. 1.6(2014): 400-406.
[2] Robert R. Alfano, et al. “The supercontinuum laser source.” Springer Science + Business (2006).
[3] Steffen Hädrich, et al. “Energetic sub-2-cycle laser with 216 W average power,” Opt. Lett. 41, (2016): 4332–4335.
[4] Balciunas, T., et al. “A strong-field driver in the single-cycle regime based on self-compression in a Kagome fibre”. Nat. Commun. 6:6117 doi: 10.1038/ncomms7117 (2015)
[5] Silva, F., et al. “ multi-octave supercontinuum generation from mid-infrared filamentation in a bulk crystal.” Nat. Commun. 3:807 doi: 10.1038/ncomms1816 (2012).
[6] Yu-Chen Cheng, et al. “ Supercontinuum generation in a multi-plate medium.” Optics Express 24.7 (2016):7224-7231.
[7] F. E. Lytle, et al. “ An Introduction to Time-Resolved Pump/Probe Spectroscopy.” Appl. Spectrosc. 39.3 (1985):444-451.
[8] Joonhee Choi, et al. “ Generation of isolated attosecond pulses using a plasmonic funnel-waveguide.” New Journal of Physics, 14, 103038 (2012).
[9] McPherson, A. et al. “ Studies of multiphoton production of vacuum-ultraviolet radiation in the rare gases.” Journal of the Optical Society of America B4.4 (1987):595-601.
[10] R. R. Alfano, et al. "Observation of self-phase modulation and small-scale filaments in crystals and glasses" Physical Review Letters 24, 592 (1970).
[11] Andrew M. Weiner, et al. “Ultrafast optics.” John Wiley & Sons (2009).
[12] Osamu Aso, et al “Four-Wave Mixing in Optical Fibers and Its Applications.” Furukawa Review, 19 (2000).
[13] Phan Huy, et al. “ Characterization of self-phase modulation in liquid filled hollow core photonic bandgap fibers.” J. Opt. Soc. Am. B.27.9 (2010): 1886-1893 .
[14] Jamal T. Manassah, et al. “ Induced phase modulation of a generated second-harmonic signal.” Opt. Lett. 12.12, (1987): 1005-1007.
[15] Anders Höök, et al. “ Influence of stimulated Raman scattering on cross-phase modulation between waves in optical fibers.” Opt. Lett. 17.2, (1992):115-117.
[16] See Leang Chin, et al. “ Femtosecond laser filamentation.” Springer Science + Business (2009).
[17] A. Couairon, et al. “ Femtosecond filamentation in transparent media.” Physics Reports 441 (2007): 47 – 189.
[18] Audrius Dubietis, et al “ Ultrafast supercontinuum generation in bulk condensed media.” Physics Optics,arXiv:1706.04356v1 (2017).
[19] F. Demartini, et al. “Self-Steepening of Light Pulses.” Physical Review 164-2 (1967).
[20] Johannes Weitenberg, et al. “ Multi-pass-cell-based nonlinear pulse compression to 115 fs at 7.5 µJ pulse energy and 300 W average power.” Optics Express 25.17 (2017): 20502-20510.
[21] K. W. Delong, et al. “Pulse retrieval in frequency‐resolved optical gating based on the method of generalized projections.” Opt. Lett., 19.24,( 1994): 2152–2154.
[22] R. Trebino, et al. “Measuring ultrashort laser pulses in the time‐frequency domain using frequency‐resolved optical gating.” Rev. Sci. Instrum., 68. 9,(1997): 3277–3295.
[23] B.E.A.Saleh, et al. “Fundamentals of Photonics, Second Edition”.
[24] J. Gagnon, et al. “The accurate FROG characterization of attosecond pulses from streaking measurements.” Appl. Phys. B 92, (2008): 25-32.
[25] B. Chimier, et al. “ Damage and ablation thresholds of fused-silica in femtosecond regime.” Phys. Rev. B 84, 094104 (2011).