共查询到20条相似文献,搜索用时 15 毫秒
1.
报道了两个增益开关调制的法布里-珀罗半导体激光器互注入锁定实验方案,可产生双波长可调谐光脉冲。该装置对两个结构基本相同的法布里珀罗半导体激光器做增益开关调制,产生多模光脉冲输出;然后利用两个光纤光栅作为滤波元件,通过调节可调谐光延迟线(VODL2),可使得双波长光脉冲在两个法布里-珀罗激光器之间相互注入锁定.从而在输出端得到高边模抑制比的双波长光脉冲输出。然后再通过应力作用在两个光纤光栅上以改变它们的反射波长和适当调整另一个可调谐光延迟线(VODLI)长度.可得到不同的双波长的光脉冲输出,而重复频率保持524.6MHz不变。在13.2nm调谐范围内边模抑制比高于25dB.系统稳定且波长调节方便。 相似文献
2.
Yi-Ming Duan 《中国物理 B》2023,32(1):17303-017303
We investigate the nonlinear optical rectification (NOR) of spherical quantum dots (QDs) under Hulthén plus Hellmann confining potential with the external tuning elements. Energy and wavefunction are determined by using the Nikiforov-Uvarov method. Expression for the NOR coefficient is derived by the density matrix theory. The results show that the applied external elements and internal parameters of this system have a strong influence on intraband nonlinear optical properties. It is hopeful that this tuning of the nonlinear optical properties of GaAs/Ga1-xAlxAs QDs can make a greater contribution to preparation of new functional optical devices. 相似文献
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Xu P Li K Zhao G Zhu SN Du Y Ji SH Zhu YY Ming NB Luo L Li KF Cheah KW 《Optics letters》2004,29(1):95-97
We present what is to our knowledge a new approach to generating tunable blue light by cascaded nonlinear frequency conversion in a single LiTaO3 crystal. Simultaneous quasi-phase matching of an optical parametric generation process and a sum-frequency mixing process is achieved by means of structuring the crystal with a quasi-periodic optical superlattice. The spectral (wavelength tuning and bandwidth) and power characteristics of the blue-light generation are studied with a fixed-wavelength 532-nm picosecond laser and a wavelength-tunable nanosecond optical parametric oscillator (OPO) as the pump sources. By tuning the OPO wavelength, we could tune the blue output over approximately 20 nm. Temperature tuning of the blue output at a fixed pump wavelength of 532 nm was limited to approximately 1.5 nm. A maximum blue power of 15 microW was generated at a pump power of 0.5 mW, corresponding to an efficiency of 3%. 相似文献
5.
Ultrahigh-speed tuning of an extended-cavity semiconductor laser is demonstrated. The laser resonator comprises a unidirectional fiber-optic ring, a semiconductor optical amplifier as the gain medium, and a novel scanning filter based on a polygonal scanner. Variable tuning rates up to 1150 nm/ms (15.7-kHz repetition frequency) are demonstrated over a 70-nm wavelength span centered at 1.32 microm. This tuning rate is more than an order of magnitude faster than previously demonstrated and is facilitated in part by self-frequency shifting in the semiconductor optical amplifier. The instantaneous linewidth of the source is <0.1 nm for 9-mW cw output power and a low spontaneous-emission background of -80 dB. 相似文献
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胡宗福 《中国光学快报(英文版)》2004,2(1)
A new kind of tunable optical filter is proposed for DWDM optical communication application. It is based on cascaded polarization interference filter (PIF). The period and bandpass width of each PIF are decided by its optical path difference between o-ray and e-ray (OPDOE). When their OPDOEs are proportionately designed, the tuning range and bandpass width depend on OPDOE in the first and the last PIF, respectively. The tuning range, bandpass width and crosstalk are independent each other. The crosstalk is related to the OPDOE ratios among PIFs and can be suppressed by designing the PIF's 15 × 2N-7 × l1, 10 × 2N-6 × l1 and 2N-2 × l1 from the first to the last. This suggested OPDOEs can yield -50-dB crosstalk for any tuning range and bandpass width. The insert loss is less than i dB. As its loose alignment requirement, there is no limitation on cascaded PIF number. When 11 PIFs are cascaded, it can achieve 170-nm tuning range, -50-dB crosstalk, bandpass width applicable to 25-GHz channel spacing and 1 dB insert loss. 相似文献
8.
We demonstrate electro-optic spectral tuning in a continuous-wave periodically poled LiNbO(3) (PPLN) optical parametric oscillator (OPO). We achieve 8.91 cm(-1) of rapid spectral tuning, with a linear tuning rate of 2.89 cm(-1) /(kV/mm), by applying electric fields up to +/-1.5 kV/mm across the crystal while it is operating within the OPO. Intentionally poling the PPLN crystal with an asymmetric domain structure enables tuning, and numerical predictions closely match the experimental observations. The tuning is considerably larger than the typical operational bandwidth of the OPO, indicating that we are in fact shifting the gain curve of the PPLN crystal. 相似文献
9.
We demonstrate continuous tuning of a terahertz quantum cascade wire laser over a broad range of ~330?GHz (~8.6% of the 3.85?THz center frequency) with single-mode operation. Tuning is achieved with a narrow laser ridge (~λ(o)/8) and a moveable MEMS (microelectromechanical systems) side object (plunger) to manipulate the transverse optical mode. The frictionless MEMS plunger enables continuous and reversible tuning. We demonstrate ~30?GHz redshift tuning using a silicon plunger and ~300?GHz blueshift tuning using a metal plunger. The blueshift tuning range is limited by the bandwidth of the gain medium rather than the tuning mechanism. 相似文献
10.
Feifei Yin Sigang Yang Hongwei Chen Minghua Chen Shizhong Xie 《Optics Communications》2012,285(10-11):2702-2706
A broadband tunable, single-longitudinal-mode (SLM) Ytterbium fiber laser with unpumped Ytterbium-doped Sagnac loop is proposed and demonstrated experimentally. The unpumped Ytterbium-doped Sagnac loop is employed as a saturable absorber based auto-tracking filter to ensure single-longitudinal-mode oscillation. And a tunable band pass optical filter with large tuning range is applied to achieve broadband tuning ability. With 1-m Ytterbium-doped fiber as the gain medium, the SLM operation is achieved with over 60-nm wavelength tuning range at 160-mW pump power. The laser is very stable with output power of about 3 dBm and optical signal to noise ratio of higher than 50 dB in all the 60-nm tuning range. 相似文献
11.
M. Vainio J. Peltola S. Persijn F. J. M. Harren L. Halonen 《Applied physics. B, Lasers and optics》2009,94(3):411-427
Stability and tuning characteristics of continuous-wave optical parametric oscillators (CW OPOs) are affected by various thermal
effects arising from optical absorption in nonlinear crystals. In this paper, we present an experimental study of such effects
in a singly resonant CW OPO. The OPO operates in the 3-μm mid-infrared region and it is based on a MgO-doped periodically
poled lithium niobate crystal. We focus our study on two thermally induced phenomena that have been recently reported to exist
in singly resonant CW OPOs: optical bi-stability and thermal self-locking. Thermal self-locking effect, which is known to
alter the stability and tuning properties of doubly and triply resonant CW OPOs, is shown to be also of importance in singly
resonant OPOs. We report the stability and tuning characteristics of a thermally loaded OPO and discuss a simple temperature-tuning
method that can be used to scan the OPO idler frequency continuously over several THz. 相似文献
12.
We demonstrate high-efficiency, wideband-tunable, laser-ablated long-period fiber gratings that use an optical polymer overlay. Portions of the fiber cladding are periodically removed by CO(2) laser pulses to induce periodic index changes for coupling the core mode into cladding modes. An optical polymer with a high thermo-optic coefficient with a dispersion distinct from that of silica is used on a deep-ablated cladding structure so that the effective indices of cladding modes become dispersive and the resonant wavelengths can be efficiently tuned. The tuning efficiency can be as high as 15.8 nm/ degrees C, and the tuning range can be wider than 105 nm (1545-1650 nm). 相似文献
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We report 20 Gb/s transmission of four-level pulse amplitude modulation(PAM) signal using a directly modulated tunable distributed Bragg reflector(DBR) laser. Transmission distance over 20 km was achieved without using optical amplifiers and optical dispersion compensation modules. A wavelength tuning range of 11.5 nm and a 3 dB bandwidth greater than 10 GHz over the entire wavelength tuning range were obtained. 相似文献
14.
本文采用折射率面来描述光参量振荡过程的物理图象,获得了光参量振荡过程的相位匹配图象和频率调谐的简单的数学表达式,直观简洁地说明了光参量振荡器频率调谐曲线的调谐行为.我们用1.06μm和0.532μm激光泵浦β-BaB2O4(BBO)晶体,获得了角度调谐的BBO光参量振荡器的调谐范围分别为1.7~2.35μm及0.72~2.1μm,最大能量转换效率为15%,还讨论了输出能量与腔长的关系. 相似文献
15.
A simple pseudoexternal cavity with a commerically available broad-area laser diode, standard optics, and a thin FabryPerot etalon provides single-mode emission with 1-W optical power and a tuning range of ~0.5nm . The linewidth is estimated at 200MHz. Such high-power semiconductor laser systems are promising light sources for atomic physics, in which narrow-band high-power light is necessary, for example, for optical pumping of alkali metal vapor. Methods for expanding the tuning range and achieving higher narrow-band optical power are discussed. 相似文献
16.
Tuning fork enhanced interferometric photoacoustic spectroscopy: a new method for trace gas analysis
M. Köhring A. Pohlkötter U. Willer M. Angelmahr W. Schade 《Applied physics. B, Lasers and optics》2011,102(1):133-139
A photoacoustic trace gas sensor based on an optical read-out method of a quartz tuning fork is shown. Instead of conventional
piezoelectric signal read-out, as applied in well-known quartz-enhanced photoacoustic spectroscopy (QEPAS), an interferometric
read-out method for measurement of the tuning fork’s oscillation is presented. To demonstrate the potential of the optical
read-out of tuning forks in photoacoustics, a comparison between the performances of a sensor with interferometric read-out
and conventional QEPAS with piezoelectric read-out is reported. The two sensors show similar characteristics. The detection
limit (L) for the optical read-out is determined to be L
opt=(2598±84) ppm (1σ) compared to L
elec=(2579±78) ppm (1σ) for piezoelectric read-out. In both cases the detection limit is defined by the thermal noise of the tuning fork. 相似文献
17.
Integrating an active medium with a filtering component can bring new functionalities compared with configurations where the two stages (units) are placed in series. We exploit this phenomenon and demonstrate all-optical tunable filters based on long-period fiber gratings written in an active optical fiber. The tuning is obtained via optical pumping at 980 nm. 相似文献
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Lin GR 《Optics letters》2000,25(11):799-801
A dc-voltage-controlled optoelectronic delay line for continuous tuning of the relative delay time of an optical pulse train generated from a gain-switched laser diode is demonstrated. A maximum tunable range delay time of 3.9 ns ( approximately 2 periods) for optical pulses at a 500-MHz repetition rate is reported, which corresponds to a phase shift of as much as 4pi. The tuning responsivity and resolution of the current apparatus are 0.54 ps/mV and <0.2 ps, respectively. The measured timing fluctuation and long-term drift at any delay time are 0.13 ps and 20 fs/min, respectively. This scheme further permits the simultaneous phase tracking of the laser pulse train to unknown signals generated from the device under test. 相似文献
20.
I. Kadenko O. Bezshyyko D. Hohov A. Sidorin G. Trubnikov N. Shurkhno R. Stassen 《Physics of Particles and Nuclei Letters》2014,11(5):705-707
To carry out longitudinal stochastic cooling of charge particle beams at the Nuclotron of the Joint Institute for Nuclear Research (Dubna), a unique optical comb filter was designed and developed. The designed filter has space-saving size, low insertion losses, and small dispersion. The comb filter tuning was automated using a specially designed software, which made it possible to reduce the tuning time and increase tuning accuracy up to several hertz. The designed filter with automatic tuning was successfully tested in an experiment on deuteron beam cooling. In this work, characteristics of the designed filter are presented and an algorithm of its automatic tuning is considered. 相似文献