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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - A 12.6 – 15 μm Mid-IR Source Based on Difference Frequency Generation in Orientation-Patterned GaAs
摘要： Tunable laser sources in the mid-infrared (mid-IR) spectral range have been of great interest for a variety of applications such as molecular spectroscopy and trace gas detection. Difference-frequency generation (DFG) based on nonlinear frequency conversion in nonlinear crystals has been an effective approach to realize tunable mid-IR laser sources [1]. Among nonlinear crystals, orientation-patterned (OP) GaAs has been highly attractive for mid-IR DFG laser sources due to its large nonlinear susceptibility, lack of birefringence, wide transparency range (0.9 – 17 μm), high thermal conductivity, and high laser-damage-threshold [2,3]. Here, we report the generation of broadly tunable mid-IR radiation across 12.65 – 15 μm based on the DFG approach using an OP-GaAs crystal.
关键词： mid-IR,difference-frequency generation,orientation-patterned GaAs,tunable laser sources,molecular spectroscopy,trace gas detection
更新于2025-09-11 14:15:04
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Sub-terahertz and terahertz generation in long-wavelength quantum cascade lasers
摘要： Terahertz quantum cascade laser sources with intra-cavity non-linear frequency mixing are the first room-temperature electrically pumped monolithic semiconductor sources that operate in the 1.2–5.9 THz spectral range. However, high performance in low-frequency range is difficult because converted terahertz waves suffer from significantly high absorption in waveguides. Here, we report a sub-terahertz electrically pumped monolithic semiconductor laser. This sub-terahertz source is based on a high-performance, long-wavelength (λ?≈?13.7 μm) quantum cascade laser in which high-efficiency terahertz generation occurs. The device produces peak output power of 11 μW within the 615–788 GHz frequency range at room temperature. Additionally, a source emitting at 1.5 THz provides peak output power of 287 μW at 110?K. The generated terahertz radiation of <2 THz is mostly attributable to the optical rectification process in long-wavelength infrared quantum cascade lasers.
关键词： integrated transitions,difference frequency generation,intersubband,cascade laser,terahertz,quantum optics devices
更新于2025-09-11 14:15:04
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Tunable Near 3-μm Difference Frequency Generation using Ytterbium and Broadband Seed Erbium Fiber Lasers
摘要： The absorption peaks corresponding to vibrational energy levels of various molecules are located in the mid-infrared (mid-IR) spectral range. For instance, the interatomic bonding of hydrogen and another heavier element (e.g. C-H, O-H, N-H) that is a part of some organic and inorganic molecules is characterized by the absorption peak located near 3μm wavelength. Laser sources operating at this wavelength can be useful tools for medical applications, non-metallic materials processing, and spectroscopy [1]. The study of the interaction of various organic substances with mid-IR radiation is rather challenging because of their great diversity and chemical composition complexity. An application of the laser source with high output power and tunable wavelength can significantly facilitate possible investigation problems [2,3]. This research is devoted to the elaboration of the tunable laser source of mid-IR radiation using single pass difference frequency generation of the pump (1.03 μm) and seed (1.55 μm) radiation in periodically poled lithium niobate (PPLN) crystal (see Fig.1 (a)). Pulsed ytterbium and erbium fiber lasers were used as the pump and seed radiation sources respectively. Both of them were assembled basing on a MOPA optical scheme, pulse duration was about 2 ns and repetition rate was 3 MHz. The average output power of Yb-laser was up to 50 W, which is five times higher than the maximum power of Er laser source. The wavelength corresponding to the difference frequency generation for these fiber lasers lies in the 3 μm region. The spectrum of the seed radiation was considerably broadened in the delivery fiber due to the four-wave mixing and Raman scattering. So that, it was possible to obtain the seed radiation in the spectral range from 1.55 m to 1.60 μm. The selective parametric amplification region of seed radiation can be shifted by changing PPLN temperature, as a result, the idler radiation wavelength tuning was achieved. We obtained the idler tuning in 2.9–3.1 μm wavelength range by changing the PPLN temperature from 45 °C to 110 °C. This tuning range was restricted by the spectral width of the Er-laser radiation. The idler radiation power varied from 5.5 W to 8.0 W in the whole tuning range (see Fig.1 (b)). The conversion efficiency reached 15% in respect to the Yb-laser power. As we were not able to measure directly the mid-IR radiation spectrum but it was derived using the experimentally measured spectrum of the amplified seed radiation. Normalized calculation results are shown in Fig.1 (c). The spectral width of the output mid-IR radiation reached 20-30 nm (at a 3 dB FWHM level).
关键词： tunable laser source,mid-infrared,difference frequency generation,PPLN crystal,erbium fiber laser,ytterbium fiber laser
更新于2025-09-11 14:15:04
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A Material for Difference-Frequency Generation of Terahertz Radiation
摘要： The possibility of efficient difference-frequency generation of terahertz radiation in a metamaterial representing a structure consisting of alternating layers of a semiconductor materials exhibiting intrinsic or metallic conductivity that can be grown by epitaxial methods is investigated theoretically.
关键词： terahertz radiation,metamaterial,epitaxial methods,difference-frequency generation,semiconductor
更新于2025-09-10 09:29:36