Teknologi Pengambilan Sampel Domain Waktu Laser Ultrashort
Since the generation of ultrashort pulses, they have been an important research tool in many scientific research fields, such as ultrafast spectroscopy, attosecond science, THz generation, etc., and the accurate acquisition of ultrashort laser pulse width is the prerequisite for the generation and application of ultrashort pulses.
Metode pengukuran tradisional seperti fotodiodes dan pengukuran autokorelasi hanya dapat mengukur amplop pulsa, tetapi tidak dapat memperoleh informasi fase dari pulsa . untuk menyelesaikan masalah ini, berbagai {Pulsa {Pulsa {pulsa {kring yang disesuaikan dengan frequency {{{{{kring yang disesuaikan dengan frekuensi ini diselipkan oleh frekuensi 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 Gerbang waktu ultrafast, seperti secara langsung menggunakan pulsa attosecond, menggunakan ionisasi tunneling, teknologi pengambilan sampel fotokonduktivitas nonlinier, dll.
Teknologi pengambilan sampel domain waktu pulsa berdasarkan gangguan proses pencampuran empat gelombang permukaan padat
Recently, the Attosecond Science and Technology Research Center of Xi'an Institute of Optics and Precision Mechanics proposed a new time-domain sampling technology for ultrashort laser pulses. This measurement technology is based on the third-order nonlinear optical effect, and obtains ultrafast time gates and samples ultrashort pulses in time domain by perturbing the solid surface four-wave mixing 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 displacement stage. Then a concave reflector is used to focus the two on the front surface of the fused quartz slice. Finally, mask2 is used to block the reflected fundamental frequency light pulse and perturbation light pulse, and a lens is used to focus the generated reflected four-wave mixing modulated signal into the optical fiber head of the spectrometer.
Pertama, perangkat eksperimental digunakan untuk mengukur pulsa ultrashort dengan panjang gelombang pusat 800 nm dan lebar pulsa sekitar 30 fs yang dihasilkan oleh sistem laser safir Ti: sapphire . Gambar 2 (a) menunjukkan bentuk gelombang dari spektrum yang sesuai {fase {{{{{{{{{{5 {{{{{{{{{{{{{{flight {{{{{{{{yang dipantulkan {{{5 { 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) sesuai dengan pulsa laser kicauan positif, dan Gambar 2 (e) dan 2 (f) sesuai dengan pulsa kicauan negatif .
Untuk memverifikasi keandalan teknologi pengambilan sampel domain waktu ultrashort, katak digunakan untuk membandingkan pulsa ultrashort . dapat dilihat dari Gambar 2 (b), 2 (d) dan 2 (f) yang diperoleh dengan katak dan tekan pengambilan sampel domain waktu {{{{{{{yang baik {{{{{{{{good 1700 nm dan lebar pulsa sekitar 50 fs berhasil diukur dengan menggunakan pengaturan eksperimental dan katak ini .
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 Sekitar 3 . 4 siklus (sekitar 9 fs) diperoleh . setelah mengoptimalkan dispersi pulsa laser setelah spektral perluasan dan penyaringan, bentuk gelombang dari fase 3-gelombang yang dipantulkan.
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 detectors cannot directly detect four-wave mixing signals. In order to further expand the scope of application of this measurement technology, the triple frequency effect will be used in the future to indirectly measure laser pulses with a wavelength range of 2600-7800 nm.
Pusat Penelitian Sains dan Teknologi Attosecond dari Institut Optik dan Mekanika Presisi Xi'an didirikan pada Mei 2021, dipimpin oleh para peneliti Zhao Wei dan Fu Yuxi . Pusat penelitian ini berfokus pada sains dan teknologi conderkon yang tinggi, condercond, dan melakukan risalah, dan melakukan riset, Laser-conder, Teknologi Laser, dan Lascle Laser Teknologi Laser, dan Teknologi Laser Laser Condercond, dan Teknologi Laser Laser-CY LASECOD-RAIN CONDONCOD-RAINCON, DAN TINGKAT LASER TINGGI TINGGI TINGGI LASER TINGGI TINGGI TINGGI TINGGI TINGGI TINGGI TINGGI TINGGI TINGGI TINGGI TINGGI TINGGI TINGGI Laser, mikroskop elektron attosecond, pencitraan ultrafast, dinamika ultrafast, fisika laser lapangan yang kuat, dll. Infrastruktur ilmiah dan teknologi utama dari Akademi Ilmu Pengetahuan Tiongkok, Rencana Penelitian Dasar Sains Sains Shaanxi, Tim Inovasi Sains dan Teknologi Shaanxi Attosecond dan Proyek Penelitian Ilmiah Lainnya,. dalam beberapa tahun terakhir, Pusat Penelitian Sains dan Teknologi Level-level-level-level-level-level tinggi telah mengatasi proses utama level-power-power-power-power-power level level tinggi-tinggi output, dan menyediakan teknologi dan perangkat inti utama untuk lokalisasi laser kelas atas dan pembangunan fasilitas laser attosecond canggih; diusulkan dan menunjukkan metode pengukuran langsung bidang laser dalam domain waktu; and broke through the key difficulties of attosecond time-resolved diffraction imaging. The Attosecond Science and Technology Research Center is driven by attosecond science and technology, conducts ultrafast scientific research represented by advanced ultrafast laser technology and ultrafast dynamics detection, and is committed to building an internationally renowned highland for ultrafast science and technology research.
