Avesta TiF-100型 钛:蓝宝石飞秒激光器

Avesta TiF-100型飞秒激光器的相关论文

Van der Waals coupling is emerging as a powerful method to engineer physical properties of atomically thin two-dimensional materials. In coupled graphene–graphene and graphene–boron nitride layers, interesting physical phenomena ranging from Fermi velocity renormalization to Hofstadter’s butterfly pattern have been demonstrated. Atomically thin transition metal dichalcogenides, another family of two-dimensional-layered semiconductors, can show distinct coupling phenomena. Here we demonstrate the evolution of interlayer coupling with twist angles in as-grown molybdenum disulfide bilayers. We find that the indirect bandgap size varies appreciably with the stacking configuration: it shows the largest redshift for AA- and AB-stacked bilayers, and a significantly smaller but constant redshift for all other twist angles.

Avesta 固体光纤激光器相关论文

Spectrally correlated photon pairs can be used to improve the performance of long-range fiber-based quantum communication protocols. We present a source based on spontaneous parametric downconversion, which allows one to control spectral correlations within the entangled photon pair without spectral filtering by changing the pump-pulse duration or the characteristics of the coupled spatial modes. The spectral correlations and polarization entanglement are characterized. We find that the generated photon pairs can feature both positive spectral correlations,decorrelation, or negative correlations at the same time as polarization entanglement with a high fidelity of 0.97 (no background subtraction) with the expected Bell state.

Avesta 固体分秒激光器相关论文

We report on the generation of broadband, high-energy femtosecond pulses centered at 1.28 μm by stimulated Raman scattering in a pressurized hydrogen cell. Stimulated Raman scattering is performed by two chirped and delayed pulses originating from a multi-mJ Ti:sapphire amplifier.The Stokes pulse carries record-high energy of 4.4 mJ and is recompressed down to 66 fs by a reflective grating pair. We characterized the short-wavelength mid-infrared source in view of energy stability, beam profile, and conversion efficiency at repetition rates of 100 and 10 Hz. The demonstrated high-energy frequency shifter will benefit intense THz sources based on highly nonlinear organic crystals.

Avesta 固体光纤激光器相关论文

We have achieved experimentally a generation of white-light few-cycle femtosecond laser pulses, using a neon-filled hollow-core fibre. The pulses observed by us are as short as 6.22 fs at the repetition rate of 1 kHz, when the input is characterized by the parameters 2.5 mJ and 33 fs. Pulse compression has been achieved using a supercontinuum produced in a static neon-filled hollow fibre, while a pair of chirped mirrors have compensated the dispersion. Our technique allows for directly tuning the pulse duration via changing the gas pressure, while maintaining near-transform-limited pulses with constant output energies and thus reducing the complications introduced by the chirped pulses. Using the measurements of the optical transmission of the fibre as a function of the gas pressure, we have testified a high enough throughput exceeding 60%. This demonstrates the successful compression that yields few-cycle femtosecond-long pulses, with a wide spectral bandwidth.