2μm声光Q开关

介绍了一种用于固体激光器调Q的2μm声光Q开关。首次使用"失配率"来表征声光器件的阻抗失配程度,并采用LC匹配网络使阻抗失配率从0.82降低到0,衍射损耗提高了1倍。该文还提出了通过减小声光介质的厚度来提高散热速率和产品可靠性的设计方案。该声光Q开关采用石英晶体作为声光互作用介质,通光方向长度45mm,有效光孔径φ3mm,在驱动功率80W时对2μm线偏光衍射损耗达到了88%。该器件用于Ho∶YA激光器中,在重复频率10kHz时,获得的单脉冲能量1.6mJ,脉冲宽度20ns。     

毛细管放电激励类氖-氩离子X光激光研究

以类氖 氩离子跃迁线为例 ,应用一维的Lagrangian程序———XDCH研究了毛细管放电碰撞机制激励软X光激光的物理机制 ;对等离子体的Z 箍缩过程和 46 9nm谱线产生增益的条件进行了讨论 ;并分析了毛细管放电装置中产生软X激光的可能性。     

Simulations of electron energy distribution of Pd-like Xe system based on OFI

X-ray laser based on OFI is a promising way to realize the table-top X-ray laser.A simple model to describe the electron energy distribution in plasma produced by circularly polarized optical-field-induced ionization is constructed on the basis of ADK tunneling ionization theory.The ionization rate,threshold intensity,residual energy and electron energy distribution of Pd-like Xe system based on optical-field-induced ionization are calculated.The results are useful to further experments on X-ray laser of Pa-like Xe system.     

Multicolor upconversion of Er3+/Tm3+/Yb3+ doped oxyfluoride glass ceramics

Er³⁺/Tm³⁺/Yb³⁺ tridoped oxyfluoride glass ceramics was synthesized in a general way. Under 980 nm LD pumping, intense red, green and blue upconversion was obtained. And with those primary colors, multicolor luminescence was observed in oxyfluoride glass ceramics with various dopant concentrations. The red and green upconversion is consistent with ⁴F_9/2 → ⁴I_15/2 and ²H_11/2, ⁴S_3/2 → ⁴I_15/2 transition of Er³⁺ respectively. While the blue upconversion originates from ¹G₄ → ³H₆ transition of Tm³⁺. This is similar to that in Er³⁺/Yb³⁺ and/or Tm³⁺/Yb³⁺ codoped glass ceramics. However the upconversion of Tm³⁺ is enhanced by the energy transfer between Er³⁺ and Tm³⁺.     

Infrared metasurface-enabled compact polarization nanodevices

Infrared metasurface, especially that having a working range covering wavelengths from 0.75 to 25 μm, has been exploited as a revolutionary tool to manipulate the properties of electromagnetic waves owing to its potential applications in military and civilian fields. It owns the capacity to steer electromagnetic waves within subwavelength scale, with full degrees of freedom such as phase, amplitude and polarization, allowing the development of a number of planar meta-devices including the metalens, hologram, wave-plate and polarimeter. In particular, polarization, which determines the interaction of electromagnetic waves with matter, is important in almost every area of science. However, conventional materials for infrared polarization control inevitably introduce extra optical components and bulky configurations, hindering future miniaturization and integration. Moreover, compared with their short wavelength counterparts, polarization nanodevices in the infrared band and especially those in the long-wavelength infrared region have been far less explored due to the loss of material and immature fabrication techniques. Here, we review recent progress in the development of infrared metasurfaces in terms of generating, manipulating and detecting the polarization on standard and higher-order Poincaré spheres. The principles, typical strategies and emerging applications of these processes are introduced. We also discuss the challenges and outlook of future developments in this emerging field.     

Microchip lasers

Microchip lasers are miniature diode-pumped solid-state devices formed by dielectrically coating thin platelets of gain media. Their simplicity and small size give them the potential for inexpensive mass production, while their cw output characteristics are comparable to those of the best conventional devices. By incorporating a thin platelet of a second material into the device, tunable cw lasers and picosecond Q-switched microchip lasers have been produced which outperform larger devices in many aspects. Electrooptically tuned devices have demonstrated a flat-band tuning response of 15 MHz/V at modulation rates from dc to 1.3 GHz. Pulses as short as 115 ps, with peak powers of 80 kW, have been generated by electrooptically Q-switched microchip lasers, and pulse repetition rates as high as 2.25 MHz have been demonstrated. Passively Q-switched devices generate pulses as short as 218 ps and produce peak powers in excess of 130 kW, without the need for switching electronics. A variety of miniature nonlinear optical devices, including harmonic generators, parametric amplifiers, parametric oscillators, and fiber-based Raman amplifiers, have been used to frequency convert the output of these lasers, accessing the entire spectrum from 5 μm to 190 nm in extremely compact optical systems.     

Wavelet time series MPARIMA modeling for power system short term load forecasting

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