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We demonstrate a single-frequency Brillouin distributed feedback laser (DFB). The DFB laser cavity was a 12.4 cm long fiber Bragg grating with a π-phase shift offset from the grating center. It exhibited a threshold of 30 mW and conversion efficiency from pump to Stokes wave as high as 27%. Higher-order Stokes waves were suppressed by more than 20 dB. The Stokes output of the laser could be obtained in either the forward or backward direction, simply by changing the orientation of the offset of the discrete phase shift with respect to the pump propagation direction. The DFB laser operated over a pump frequency range of 1.2 GHz, more than 60 times larger than the SBS gain bandwidth. 相似文献
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Two-photon fabrication of organic solid-state distributed feedback lasers in rhodamine 6G doped SU-8
We report the fabrication of distributed feedback lasers in Rhodamin 6G doped SU-8 by direct femtosecond laser writing. The devices are fabricated by point-by-point exposure and consist of a core layer with a low-order Bragg grating on the surface. A quarter-wavelength phase shift is introduced in the middle of the grating section to obtain single-mode emission. Lasing at different wavelengths is demonstrated by changing the grating pitch. Spectral emission, threshold and lifetime characterization is performed by pumping the laser with a pulsed, frequency double Nd:YAG laser. 相似文献
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We demonstrate fiber distributed feedback (DFB) lasers using Raman gain in two germanosilicate fibers. Our DFB cavities were 124 mm uniform fiber Bragg gratings with a π phase shift offset from the grating center. Our pump was at 1480 nm and the DFB lasers operated on a single longitudinal mode near 1584 nm. In a commercial Raman gain fiber, the maximum output power, linewidth, and threshold were 150 mW, 7.5 MHz, and 39 W, respectively. In a commercial highly nonlinear fiber, these figures improved to 350 mW, 4 MHz, and 4.3 W, respectively. In both lasers, more than 75% of pump power was transmitted, allowing for the possibility of substantial amplification in subsequent Raman gain fiber. 相似文献
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W. Holzer A. Penzkofer T. Pertsch N. Danz A. Bräuer E.B. Kley H. Tillmann C. Bader H.-H. Hörhold 《Applied physics. B, Lasers and optics》2002,74(4-5):333-342
Wave-guided thin-film distributed-feedback (DFB) polymer lasers are fabricated by spin coating a PPV-derived semiconducting
polymer, thianthrene-DOO-PPV, onto oxidised silicon wafers with corrugated second-order periodic gratings. The gratings are
written by reactive ion beam etching. Laser action is achieved by transverse pumping with picosecond laser pulses (wavelength
347.15 nm, duration 35 ps). The DFB-laser surface emission and edge emission are analysed. Outside the grating region the
polymer film is used for comparative wave-guided travelling wave laser (amplified spontaneous emission (ASE)) studies. The
pump pulse threshold energy density for wave-guided DFB-laser action (4–9 μJ cm-2) is found to be approximately a factor of two lower than the threshold for wave-guided travelling wave laser action. The
spectral width of the DFB laser (down to ΔλDFB≈0.07 nm) is considerably narrower than that of the travelling wave laser (ΔλTWL≈14 nm). The DFB-laser emission is highly linearly polarised transverse to the grating axis (TE mode). Only at high pump pulse
energy densities does an additional weak TM mode build up. The surface-emitted DFB-laser radiation has a low divergence along
the grating direction. For both the DFB lasers and the travelling wave lasers, gain saturation occurs at high excitation energy
densities.
Received: 7 January 2002 / Revised version: 15 February 2002 / Published online: 14 March 2002 相似文献
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Dual-wavelength distributed Bragg reflector semiconductor laser based on composite resonant cavity 下载免费PDF全文
We report a monolithic integrated dual-wavelength laser diode based on a distributed Bragg reflector (DBR) composite resonant cavity. The device consists of three sections, a DBR grating section, a passive phase section, and an active gain section. The gain section facet is cleaved to work as a laser cavity mirror. The other laser mirror is the DBR grating, which also functions as a wavelength filter and can control the number of wavelengths involved in the laser action. The reflection bandwidth of the DBR grating is fabricated to have an appropriate value to make the device work at the dual-wavelength lasing state. We adopt the quantum well intermixing (QWI) technique to provide low-absorption loss grating and passive phase section in the fabrication process. By tuning the injection currents on the DBR and the gain sections, the device can generate 0.596 nm-spaced dual-wavelength lasing at room temperature. 相似文献
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Dual-wavelength distributed Bragg reflector semiconductor laser based on a composite resonant cavity 下载免费PDF全文
We report a monolithic integrated dual-wavelength laser diode based on a distributed Bragg reflector (DBR) composite resonant cavity. The device consists of three sections, a DBR grating section, a passive phase section, and an active gain section. The gain section facet is cleaved to work as a laser cavity mirror. The other laser mirror is the DBR grating, which also functions as a wavelength filter and can control the number of wavelengths involved in the laser action. The reflection bandwidth of the DBR grating is fabricated to have an appropriate value to make the device work at the dual-wavelength lasing state. We adopt the quantum well intermixing (QWI) technique to provide low-absorption loss grating and passive phase section in the fabrication process. By tuning the injection currents on the DBR and the gain sections, the device can generate 0.596 nm-spaced dual-wavelength lasing at room temperature. 相似文献
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π相移光纤光栅用于水中超声传感时,超声波沿光纤轴向入射和垂直光纤入射时的传感波形及幅度显著不同。针对这一现象,本文建立了基于光学传递矩阵的光纤光栅声传感理论模型,计算了超声波分别沿轴向和沿垂直方向入射时π相移光纤光栅中的非均匀应变场分布,进而分析了光谱偏移,揭示了两种入射角度下π相移光纤光栅的传感特性与声传播导致的应变场分布相关,并通过实验进行了验证。结果表明,两种入射角度产生的不同的非均匀应变场分布对π相移光纤光栅的传感特性影响明显。超声波垂直入射时的传感波形和幅度均优于轴向入射,且π相移处对传感有显著作用。当入射位置远离π相移处时,垂直入射的响应也明显降低。本研究可为π相移光纤光栅超声传感的机理分析提供参考。 相似文献
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D. Barat J. Angellier A. Vicet Y. Rouillard L. Le Gratiet S. Guilet A. Martinez A. Ramdane 《Applied physics. B, Lasers and optics》2008,90(2):201-204
We report on Fabry–Pérot semiconductor lasers and single frequency distributed feedback lasers based on GaInAsSb/AlGaAsSb
quantum wells. The laser structures were grown by molecular beam epitaxy on GaSb substrates. The devices were etched either
by wet process or by inductively coupled plasma (ICP) process. Electron-beam lithography was used to deposit a metal Bragg
grating on each side of the laser ridge to fabricate the DFB lasers. The devices all operate in the continuous wave regime
at room temperature with a single frequency emission above 2.6 μm and good tuning properties, making them well adapted to
tunable diode laser absorption spectroscopy.
PACS 42.55.Px; 42.62.Fi 相似文献
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Ngo NQ 《Optics letters》2007,32(23):3402-3404
A theoretical study of a new application of a simple pi-phase-shifted waveguide Bragg grating (PSWBG) in reflection mode as a high-speed optical dark-soliton detector is presented. The PSWBG consists of two concatenated identical uniform waveguide Bragg gratings with a pi phase shift between them. The reflective PSWBG, with grating reflectivities equal to 0.9, a free spectral range of 1.91 THz, and a nonlinear phase response, can convert a 40 Gbit/s noisy dark-soliton signal into a high-quality 40 Gbit/s return-to-zero signal with a peak power level of approximately 17.5 dB greater than that by the existing Mach-Zehnder interferometer with free spectral range of 1.91 THz and a linear phase response. 相似文献
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A novel method is proposed that simultaneously eliminates chirp and compresses pulses from gain-switched distributed-feedback Bragg (G-S DFB) semiconductor laser employing chirped fiber Bragg grating (FBG) with narrow bandwidth. It is demonstrated that with this method, only the central frequency of the FBG is slightly shifted from the central frequency of the G-S DFB laser; the nearly transform-limited narrow pulse with symmetrical waveform can be obtained. 相似文献
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基于扫描激光的腔增强吸收光谱研究 总被引:3,自引:0,他引:3
介绍了一种建立在半导体激光扫描基础上的腔增强吸收光谱技术。简要介绍了从衰荡吸收光谱技术向腔增强吸收光谱的发展及腔增强吸收光谱的实验装置,实验证明能够将 DFB 型半导体激光与高精密光学谐振腔相结合,用简单的实验装置进行高灵敏、高分辨直接吸收光谱测量。实验中,激光器的输出波长用一台波长计精确测量,当激光器的输出频率与某一腔模的频率共振时,激光被耦合到一个用两块高反射率平凹透镜(在 1.572μm 附近,R~0.994)组成的 34cm 长的高精密光学谐振腔,通过测量激光透过谐振腔后的光强,得到了二氧化碳分子在6358.654cm-1附近的吸收光谱,探测灵敏度达到了 1.2×10-5cm-1。 相似文献
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We have successfully demonstrated a single-frequency distributed-feedback (DFB) thulium-doped silica fiber laser emitting at a wavelength of 1735 nm. The laser cavity is less than 5 cm long and is formed by intracore UV-written Bragg gratings with a phase shift. The laser is pumped at 790 nm from a Ti:sapphire laser and has a threshold pump power of 59 mW. The laser has a maximum output power of 1 mW in a single-frequency, single-polarization radiation mode and is tunable over a few nanometers. To the best of the authors' knowledge, this is the first report of a single-frequency DFB fiber laser that uses thulium as the amplifying medium. The lasing wavelength is the longest demonstrated with DFB fiber lasers and yet is among the shortest obtained for thulium-doped silica fiber lasers. 相似文献
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B. Neto A. Klingler C. Reis R.P. Dionísio R.N. Nogueira A.L.J. Teixeira P.S. André 《Optics Communications》2011,284(5):1354-1356
In this paper, we propose a method to mitigate the temporal power transients arising from Erbium doped fiber amplifiers (EDFAs) on packeted/bursty scenario. The technique, applicable on hybrid WDM/TDM-PON for extended reach, is based on a low power clamping provided by a distributed feedback (DFB) laser and a fiber Bragg grating (FBG). An improvement in the data signal Q factor was achieved keeping the clamping control signal with a low power, accompanied by a maximum reduction in the gain excursion of 1.12 dB. 相似文献