Tehnologija vzorčenja laserske pulzne domene Ultrashort Laser
Od generacije ultrashortnih impulzov so bile pomembno raziskovalno orodje na številnih znanstvenih raziskovalnih področjih, kot so ultra hitra spektroskopija, atosekundna znanost, generacija THz itd.
Tradicionalne metode merjenja, kot so fotodiode in meritve avtokorelacije, lahko izmerijo samo ovojnico impulza, vendar ne morejo pridobiti faznih informacij impulza ., da bi rešili to težavo, so se razvile različne ultrashortne merilne tehnike impulza, kot je optično reševanje (D-SCAN) (D-SCAN) are indirect methods that rely on reconstruction algorithms. Compared with indirect measurement methods, direct measurement methods use ultrafast time gates to directly sample ultrashort pulses in the time domain. Therefore, for direct measurement methods, the core lies in how to obtain ultrafast time gates. At present, there are many ways to form Ultra hitri časovni vrat, na primer neposredno z uporabo atosekundnih impulzov, z uporabo ionizacije tuneliranja, nelinearne tehnologije vzorčenja fotokonduktivnosti itd.
Tehnologija vzorčenja časovne domene, ki temelji na vznemirjenju štirinožnega procesa mešanja s trdnim površino
Pred kratkim je Atosekundna znanstvena in tehnološka raziskovalna središče Xi'AN Inštituta za optiko in natančnost predlagal novo tehnologijo vzorčenja časovne domene za ultrashortne laserske impulze . Ta merilna tehnologija temelji na nelinearnem optičnem učinku tretjega reda in pridobijo ultrafastarske čase in vzorce ultrahortskih vrat in vzorcev ultrahortnih vrat in vzorcev ultrahortskih vrat in vzorcev ultrahortskih vrat in vzorcev ultrahortskih vrat in vzorcev ultrahortskih vrat in vzorcev ultrahortskih vrat in vzorcev ultrahortskih vrat in vzorcev ultrahortskih vrat in vzorcev ultrahortskih vrat in vzorcev ultrahortnih vrat in vzorcev ultrahortnih vrat in vzorcev ultrahortnih vrat in vzorcev Ultrahort PULS-o process. The ultrashort pulse time-domain sampling device is shown in Figure 1. First, the ultrashort pulse is divided into two laser pulses, namely the fundamental frequency light pulse and the perturbation light pulse, by mask1, and the relative delay τ between the two is controlled by a D-shaped mirror and a piezoelectric ceramic Stopnja premika . Nato se uporablja konkavni reflektor za osredotočenost na sprednjo površino fused kremenčeve rezine . Končno se maska2 uporablja za blokiranje odsevne temeljne frekvenčne svetlobne impulze in modulacijske luči, lečo pa se uporabi za osredotočenost generiranega moduliranega signala v modulirano modulirano modulirano modulirano modulirano modulirano modulirano modulacijsko signal v modulirano modulirano modulirano modulacijsko signal v modulirano modulirano modulacijo v štiri-valovi
First, the experimental device was used to measure ultrashort pulses with a central wavelength of 800 nm and a pulse width of about 30 fs generated by a Ti:Sapphire laser system. Figure 2(a) shows the waveform of the reflected four-wave mixing modulation signal measured after filtering. The corresponding spectrum and phase in the frequency domain are shown in Figure 2(b). It can be seen that the phase is flat at this time, almost a horizontal line. Then, by changing the dispersion of the perturbation light pulse, the perturbation light pulse under different chirps was measured. The measurement results are shown in Figures 2(c)-(f). Figures 2(c) and 2 (d) ustrezajo pozitivnim laserskim impulzom CHIRP, slike 2 (e) in 2 (f) pa ustrezajo negativnim chirp impulzi .
In order to verify the reliability of the ultrashort pulse time domain sampling technology, FROG was used to compare the ultrashort pulses. It can be seen from Figures 2(b), 2(d) and 2(f) that the results obtained by FROG and the time domain sampling technology are in good agreement. Subsequently, ultrashort pulses with a central wavelength of 1700 nm in impulzno širino približno 50 fs smo uspešno izmerili z uporabo te eksperimentalne nastavitve in žabe .
Since the sampling process occurs on the solid surface, the phase matching condition can be automatically satisfied, so this measurement technology is suitable for measuring few-cycle or even single-cycle pulses. Subsequently, a multi-thin-slice post-compression system was built based on the Ti:Sapphire laser system, and a few-cycle pulse with a central wavelength of 800 nm and a conversion limit of about 3 . 4 cikli (približno 9 fs) smo dobili . Po optimizaciji disperzije laserskega impulza po spektralnem širjenju in filtriranju je valovna oblika odsevanega štirivalnega mešalnega signala prikazana na sliki 3 (a), njegov ustrezni spekter pa je približno 12 F {16}.
The above measurement results show that the ultrashort pulse time domain sampling technology is suitable for characterizing short-cycle and few-cycle laser pulses. At present, the applicable wavelength based on the existing silicon-based and InGaAs detectors is 200-2600 nm. For laser pulses with a wavelength exceeding 2600 nm, traditional Detektorji ne morejo neposredno zaznati štirivaljnih mešalnih signalov . Za nadaljnjo razširitev obsega uporabe te merilne tehnologije se bo v prihodnosti uporabil trikratni frekvenčni učinek za posredno merjenje laserskih impulzov z valovnim območjem 2600-7800}}.
The Attosecond Science and Technology Research Center of the Xi'an Institute of Optics and Precision Mechanics was established in May 2021, led by researchers Zhao Wei and Fu Yuxi. The research center focuses on attosecond science and technology, and conducts research on high-power advanced laser technology, mid-infrared femtosecond laser, few-cycle laser technology, soft X-ray attosecond Laser, atosekundna elektronska mikroskop, ultrafast slikanje, ultrafast dinamika, močna terenska laserska fizika itd. of major scientific and technological infrastructure of the Chinese Academy of Sciences, Shaanxi Natural Science Basic Research Plan, Shaanxi Attosecond Science and Technology Innovation Team and other scientific research projects. In recent years, the Attosecond Science and Technology Research Center has overcome the key processes and technologies of high-power thin-film lasers, achieved 1 kHz, 200 mJ-level picosecond laserski izhod in so zagotavljali ključne temeljne tehnologije in naprave za lokalizacijo višjega cenovnega razreda in gradnjo naprednih atosekundnih laserskih objektov; predlagali in pokazali neposredno metodo merjenja laserskega polja v časovni domeni; in se lotil ključnih težav z atosekundnim časovno ločenim difrakcijskim slikanjem . Center za raziskovanje znanosti in tehnologije Attosecond, ki ga poganja AttoseCond Science and Technology, izvaja ultrafastične znanstvene raziskave, ki jih predstavljajo napredne ultrafastične laserske tehnologije in ultrafast dinamike in ultrafast dinamika in je zavezana gradnji mera in se zavezana k gradnji mera in tehnologije, ki je notranje in notranje pozidalo, in je zavezano, da je notranje gradnja in je nameščena v gradnjo mera in tehnologije, ki je notranje pozidanje in se zaveže
