共查询到20条相似文献,搜索用时 15 毫秒
1.
The experimental results of a high-power 3.8 μm tunable laser are presented on a quasi-phase-matched single-resonated optical parametric oscillator in PPMgO:CLN pumped by a 1064 nm laser of an elliptical beam. Theoretical analyses of the PPMgO:CLN wavelength tuning are presented. The pump source was an acousto-optical Q-switched cw-diode-side-pumped Nd:YAG laser. The beam polarization matched the e-ee interaction in PPMgO:CLN. When the crystal was operated at 90 °C and the pump power was 150 W with a repetition rate of 10 kHz, average output power of 22.6 W at 3.86 μm and 63 W at 1.47 μm was obtained. The slope efficiency of the 3.86 μm laser with respect to the pump laser was 17.8%. The M2 factors of the 3.86 μm laser were 1.74 and 4.86 in the parallel and perpendicular directions, respectively. The mid-IR wavelength tunability of 3.7-3.9 μm can be achieved by adjusting the temperature of a 29.2 μm period PPMgO:CLN crystal from 200 °C to 30 °C, which basically is accorded with the theoretic calculation. 相似文献
2.
We describe a widely tunable synchronously pumped coherent source based on the process of narrowband parametric amplification in a dispersion-shifted fiber. Using an experimental fiber with a zero-dispersion wavelength of 1590 nm and pump wavelengths of 1530 to 1570 nm yields oscillations at 1970 to 2140 nm-the longest reported wavelength for a fiber parametric oscillator. The long-wavelength oscillations are accompanied by simultaneous short-wavelength oscillations at 1200 to 1290 nm. The parametric gain is coupled to stimulated Raman scattering. For parametric oscillations close to the Raman gain peak, the two gain processes must be discriminated from each other. We devised two configurations that achieve this discrimination: one is based on the exploitation of the difference in group delay between the wavelengths where Raman and parametric gain peak, and the other uses intracavity polarization tuning. 相似文献
3.
4.
We demonstrated stable pulses generation at 2 μm in a passively Q-switched thulium-doped fiber laser using a few layer graphene thin film. The maximum output power was 4.5 mW and the single pulse energy was 85 nJ at 53 kHz repetition rate, and the pulse width was about 1.4 μs. The pulse width and the repetition rate of the Q-switched fiber laser can be changed along with the pump power. To the best of our knowledge, this is the first report of graphene saturable absorber for passively Q-switched 2 μm fiber lasers. 相似文献
5.
In this paper we present the simulation of Metal-Semiconductor-Metal photodetector (MSM-PD) of interdigitated planar structure based on InAlAs/InGaAs adapted for photodetection at the wavelength 1.55 μm. We use the theoretical models to plot the variations of the dark current, the photocurrent, the capacity, and the cut-off frequency of the photodetector as a function of bias voltage and the interelectrode distance. The obtained results show a very low dark current, mainly due to the introduction of a thin layer to increase the Schottky barrier based on In0.52Al0.48As in the epitaxial structure of component. The obtained photocurrent and cut-off frequencies are very appreciable, these latter are mainly limited by the transit time of the photo-generated carriers given the low component capacity obtained by simulation. 相似文献
6.
R. Andrew Sims Christina C.C. Willis Timothy S. McComb Vikas Sudesh Menelaos K. Poutous Martin Richardson 《Optics Communications》2011,284(7):1988-739
Output beams from three independently frequency-stabilized thulium master-oscillator power-amplifier fiber laser systems were spectrally combined using a plane-ruled metal diffraction grating. Two laser channels were frequency-stabilized with guided mode resonance filters and the third was stabilized using a plane-ruled metal diffraction grating. The systems had output wavelengths between 1984 and 2015 nm, each with a spectral width of 100-450 pm and output powers between 40-120 W. The combined beam had powers up to 49 W and was 32% efficient with respect to the launched pump power. 相似文献
7.
Ilya Mingareev Fabian Weirauch Alexander Olowinsky Lawrence Shah Pankaj Kadwani Martin Richardson 《Optics & Laser Technology》2012,44(7):2095-2099
Absorber-free transmission and butt-welding of different polymers were performed using thulium fiber laser radiation at the wavelength 2 μm. The relations between the laser process conditions and the dimensions and quality of the seam were investigated by means of optical and phase-contrast microscopy. Mechanical properties of the weld joints were studied in tensile strength tests. Laser-welded polyethylene samples revealed a tensile strength of greater than 80% of the bulk material strength. Transmission welding of different polymer combinations featured the formation of different joint classes depending on the spectral properties. The experiments demonstrate new application areas of mid-IR fiber laser sources for materials processing. 相似文献
8.
The operation of a continuous-wave mode-locked silver gallium selenide (AgGaSe2) optical parametric oscillator (OPO) is reported. The OPO was synchronously excited by 120-fs-long pulses of 1.55-μm radiation
at a repetition rate of 82 MHz. The 1.55-μm radiation is generated by a noncritically phasematched cesium-titanyl-arsenate
(CTA)-OPO pumped by a mode-locked Ti:sapphire laser. The AgGaSe2-OPO generates signal and idler radiation in the range from 1.93 μm to 2.49 μm and from 4.1 μm to 7.9 μm, respectively. Up
to 67 mW of signal wave output power has been obtained. The experimentally determined pulse duration and chirp parameters
are in reasonable agreement with results from a numerical model taking into account group velocity mismatch, group velocity
dispersion, self phase modulation, and chirp enhancement.
Received: 6 August 1999 / Revised version: 4 October 1999 / Published online: 3 November 1999 相似文献
9.
Haiyong Zhu Ge Zhang Chenghui Huang Yong Wei Lingxiong Huang Yidong Huang 《Optics Communications》2009,282(4):601-604
An eye-safe, high peak power optical parameter oscillator (OPO) intracavity pumped by electro-optic Q-switched Nd:YAG laser is presented. This OPO is based on a 20 mm length KTiOAsO4 crystal with non-critical phase matching (θ = 90°, ?=0°) cut. An aperture ∅3 mm acted as limiting diaphragm to get good beam quality of pumping laser. The output energy of 25 mJ at the signal wavelength 1.53 μm was obtained with repetition rate of 1 Hz. The highest peak power intensity was up to 88 MW/cm2 with pulse width of 4 ns. Without diaphragm, the maximum output energy of 90 mJ was achieved with area of light spot (∅6 mm) four times larger, but the peak power intensity was lower. 相似文献
10.
A Tm–Ho codoped fiber amplifier system is built. And, amplification of a gain-switched Tm–Ho codoped fiber laser is investigated. Average output of 300 mW is obtained at repetition rate of tens of kHz with an amplification gain bigger than 11 dB. And, pulse amplification efficiency of resonantly pumped Tm–Ho codoped single clad fiber is comparable with 793 nm pumped Tm-doped double clad fiber. The maximal pulse energy generated is about 13.1 μJ, corresponding to a peak power of 282 W at 20 kHz. During the amplification process, gain-switching, partially modulated gain-switched mode-locking and 100% modulated gain-switched mode-locking are observed sequentially. At gain-switching mode, the laser output enjoys a narrow linewidth of 0.31 nm, while at gain-switched mode-locking mode, the spectral linewidth broadens to 0.6 nm. 相似文献
11.
Franck Bielsa Khelifa Djerroud Albane Douillet Tristan Valenzuela Christophe Daussy Anne Amy-Klein 《Journal of Molecular Spectroscopy》2008,247(1):41-46
We report on highly accurate absolute frequency measurement against a femtosecond frequency comb of six saturated absorption lines of formic acid (HCOOH) with an accuracy of 1 kHz. We also report the frequency measurement of 17 other lines with an accuracy of 2 kHz. Those lines are in quasi coincidence with the 9R(36) to 9R(42) CO2 laser emission lines and are probed either by a CO2 or a widely tunable quantum cascade laser phase locked to a master CO2 laser. The stability of HCOOH stabilized lasers is characterized by a fractional Allan deviation of 3.1 × 10−12 τ−1/2. They give suitable frequency references for Doppler-free two-photon spectroscopy. 相似文献
12.
Ho3+-doped low-phonon-energy heavy-metal gallate glasses (LKBPBG) have been prepared and efficient 1.199 μm emission originating from the 5I6 → 5I8 radiative transition has been observed under 900 nm excitation. The spontaneous emission probability and the maximum stimulated emission cross-section were derived to be 294.31 s− 1 and 3.46 × 10− 21 cm2, respectively. The ratio of quantum yields between ~ 1.2 and ~ 2.0 μm emissions was identified to be 16%, demonstrating that the 5I6 → 5I8 transition is favorable for optical amplification. The maximum gain coefficient of 1.84 dB/cm at 1.199 μm wavelength was anticipated in the ideal status. These results indicate that the Ho3+-doped LKBPBG glasses have a promising potential for the development of ~ 1.2 μm signal amplifier devices. 相似文献
13.
V. S. Airapetyan 《Journal of Applied Spectroscopy》2009,76(2):268-272
We have developed, built, and tested an automated differential lidar system for measuring low concentrations of atmospheric
gases, based on an optical parametric oscillator tunable in the near IR region. We have calculated the spectral shift of the
relative intensities of the individual lines in the ν3 absorption band of methane. In comparing the measured and calculated spectra, we did not observe any shifts in the ν3 absorption band of methane. At the same time, in the experimental spectra we observe broadening of the Q branch and the individual lines of the P branch.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 76, No. 2, pp. 285–290, March–April, 2009. 相似文献
14.
We investigate characteristics of gold metal strip waveguides based on long range surface plasmon polaritons (LRSPPs) along thin metal strips embedded in a polymer for practical applications at the telecommunication wavelengths of 1.31 and 1.55 μm. Guiding properties of the gold strip waveguides are theoretically and experimentally evaluated with the limited thickness and width up to ∼20 nm and ∼10 μm, respectively. The lowest propagation loss of ∼1.4 dB/cm is obtained with a 14.5-nm-thick and 2-μm-wide gold strip at 1.55 μm. With a single-mode fiber, the lowest coupling loss of ∼0.4 dB/facet is achieved with a 14.5-nm-thick and 5-μm-wide gold strip at 1.55 μm. The lowest insertion losses are obtained 8-9 dB with 1.5 cm-long gold strips of a limited thickness and width at both the wavelengths. We demonstrate a 10 Gbps optical signal transmission via the LRSPP waveguide with a 14 nm-thick, 2.5 μm-wide, and 4 cm-long gold strip. These LRSPP waveguides have potential applications for optical interconnects and communications. 相似文献
15.
Hyukjoon KwonWon-Kye Baek Myung-Sin KimWan-Soon Shin Jack J. Yoh 《Optics and Lasers in Engineering》2012,50(2):114-121
We measured the temperature-dependent absorptance of metals (Al, Ti, SS304) for continuous beams from 1.07 μm fiber laser and 10.6 μm CO2 laser using power sensors and infrared (IR) pyrometers. The absorptance measurements were repeated for metals with three different paint coatings. For measurements at elevated temperatures up to the melting point, integrating sphere is not practical since high temperature radiation from a heated target disturbs weak output from the sphere considerably. Our results provide how each metal, whether coated or uncoated, absorbs the infrared beams as temperature is elevated to a melting point. A polynomial approximation to the measured absorptance of each target is provided for modeling of the laser-metal interaction at elevated temperatures. 相似文献
16.
An all-solid-state mid-infrared optical parametric generator with wide tunability by using multi-grating periodically poled 5 mol.-% MgO-doped lithium niobate (MgO:PPLN) is reported. The pump source is a diode-pumped Q-switched Nd:GdVO4 laser operated at 1.342 μm with pulse width of 150 ns and repetition rate of 50 kHz. To extend the interaction length, two identical multi-grating MgO:PPLN crystals have been cascaded in the OPG system. When the incident pump average power is 10 W, the obtained maximum idler output power is 340 mW at 4.144 μm. Compared with only using one multi-grating MgO:PPLN crystal, the obtained idler output power increases by 20.1%. 4.144-4.851 μm continuous-tunable idler output is obtained with six grating periods from 29 to 31.5 μm and temperature from 40 to 200 °C. To our knowledge, this is the first time to use 1.342 μm laser as the pump source of OPG. 相似文献
17.
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
18.
X. Thomas 《Journal of Quantitative Spectroscopy & Radiative Transfer》2010,111(9):1080-10048
Infrared high resolution spectra of ozone 16O3 have been recorded in the 10 and 5 μm spectral ranges in order to derive their absolute intensities with a best achievable accuracy. Spectra have been recorded with the home made stepping mode FTS of GSMA (Reims). In the two spectral regions, we use UV-IR crossed beam cell. The quantification of ozone is achieved using UV cross section at 253.65 nm. A check of this UV calibration is also performed using direct pressure measurements of quasi-pure samples of O3. The intensities are derived from infrared spectra using multifit procedure already tested. In the 10 μm range, where 12 different spectra have been recorded, 65 well selected lines led to a good agreement (better than 0.3%) with the HITRAN 2008 (or 2004) values, confirming our previous work [De Backer-Barilly MR, Barbe A. Absolute intensities of the 10 μm bands of 16O3. J Mol Spectrosc 305:2001;43-53]. In the 5 μm range, where 18 transitions are selected, we also note a correct agreement with HITRAN 2008, despite a slightly larger averaged value between (1.9%) experimental and theoretical (HITRAN). As conclusion, authors suggest the use of current HITRAN 2008 data for atmospheric retrievals. 相似文献
19.
Jeremy J. Harrison Nicholas D.C. Allen Peter F. Bernath 《Journal of Quantitative Spectroscopy & Radiative Transfer》2011,112(1):53-58
Infrared absorption cross sections for acetone (propanone), CH3C(O)CH3, have been determined in the 3 μm spectral region from spectra recorded using a high-resolution FTIR spectrometer (Bruker IFS 125 HR) and a multipass cell with a maximum optical path length of 19.3 m. The spectra of mixtures of acetone with dry synthetic air were recorded at 0.015 cm−1 resolution (calculated as 0.9/MOPD using the Bruker definition of resolution) at a number of temperatures and pressures (50-760 Torr and 195-296 K) appropriate for atmospheric conditions. Intensities were calibrated using three acetone spectra (recorded at 278, 293 and 323 K) taken from the Pacific Northwest National Laboratory (PNNL) IR database. 相似文献
20.
In this work, first-principles modeling techniques are used to investigate the mechanism(s) of adsorption of molecular oxygen on the GaAs(0 0 1)-(2 × 4) surface. The reaction of adsorption was modeled using ab-initio molecular dynamics at constant temperature for two thermal regimes, i.e. 300 K and 680 K, respectively. The resulting adsorbate configurations were relaxed using density functional theory and the adsorption energies were subsequently computed. Our results suggest a dominant mechanism of adsorption described by molecular dissociation, followed by oxygen insertion in the Ga-As bonds, bridging Ga-O-As chemical bonds. The electronic properties of the clean reconstructed GaAs(0 0 1) surface and the ones obtained after O2 adsorption were computed. It is found that for the most stable adsorbate configuration, where oxygen is incorporated in a Ga-O-As unit, the associated density of electronic states is free of defect levels within the GaAs band gap region. 相似文献