共查询到20条相似文献,搜索用时 171 毫秒
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Based on the physical fact that a laser containing a gain medium with homogenous line broadening oscillates at the wavelength which requires the smallest threshold gain due to the mode competition effect, after taking into account the wavelength-depended reflectivity distribution profile of a fiber Bragg grating, the oscillation wavelength λl of fiber Bragg grating semiconductor lasers has been investigated theoretically. The results show that the laser oscillation wavelength λB is not fixed at the Bragg reflection wavelength λl of fiber Bragg grating, and the offset between λB and λl depends on the reflectivity distribution profile of fiber Bragg grating and the gain profile of semiconductor gain medium. 相似文献
3.
A simplified ring cavity for achieving a unidirectional room temperature multi-wavelength erbium-doped fiber ring laser without optical isolator is demonstrated. The fiber ring cavity is built in such a way that the optical fields propagating in two directions suffer different losses caused by one sampled fiber Bragg grating. Furthermore, simultaneous multi-wavelength lasing with 0.8-nm intervals is demonstrated with sinusoidal phase modulation just before the sampled fiber Bragg grating to prevent single-wavelength lasing and unstable wavelength oscillation. 相似文献
4.
Mohd Nasir M. N. Al-Mansoori M. H. Abdul Rashid H. A. Choudhury P. K. Yusoff Z. 《Laser Physics》2008,18(4):446-448
In this paper, we demonstrate a multiwavelength Brillouin erbium fiber laser in a Fabry-Perot cavity. The design utilized a bidirectional oscillation provided by a fiber Bragg grating filter and a fiber loop mirror at each end of the laser cavity. A stable operation of 25 Brillouin-Stokes lines was obtained at around a 1559-nm band. 相似文献
5.
S. R. Abdullina S. A. Babin A. A. Vlasov S. I. Kablukov 《Optics and Spectroscopy》2007,103(6):1007-1011
A tuning method of a fiber Bragg grating by the bending compression-tension is considered. With this method, a relative tuning range of the resonance wavelength of the grating of about 5% has been obtained. The changes in the shape of the spectrum and in the grating reflectivity during the tuning process are studied. The reflectivity of the fiber Bragg grating has been found to considerably increase with increasing degree of compression. It is shown that such an increase is caused by compression-induced changes in the refractive index modulation amplitude in the grating. The fiber Bragg grating developed has been applied for tuning the radiation wavelength of an ytterbium fiber laser. The tuning range of the laser has been found to be 45 nm around the central wavelength 1080 nm. 相似文献
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We demonstrate a wavelength-tunable, passively mode-locked erbium-doped fiber laser based on graphene and chirped fiber Bragg grating. The saturable absorber used to enable passive mode-locking in the fiber laser is a section of microfiber covered by graphene film, which allows light-graphene interaction via the evanescent field of the microfiber. The wavelength of the laser can be continuously tuned by adjusting the chirped fiber Bragg grating, while maintaining mode-locking stability. Such a system has high potential in tuning the mode-locked laser pulses across a wide wavelength range. 相似文献
7.
We demonstrated a fiber sensing system using the method of wavelength locking of two identical fibers Bragg gratings (FBG) to interrogate the wavelength shift by directly measuring the intensity of the reflection from the sensing Bragg grating. The light source of the fiber sensing system is an EDFA fiber ring laser pumped by a 980 nm laser diode and a narrow bandwidth fiber Bragg grating for the filter of the ring laser resonator. The wavelength shift is converted to the intensity deviation of the reflection from the sensing FBG under strain variation, and is able to achieve real-time sensing of the dynamic strain sensing in civil engineering. The characteristics and key factors to maintain stability of the dynamic strain sensing system are discussed. 相似文献
8.
D. Liu N.Q. Ngo X.Y. Dong S.C. Tjin P. Shum 《Applied physics. B, Lasers and optics》2005,81(6):807-811
We propose and experimentally demonstrate a stable dual-wavelength erbium-doped polarization-maintaining (PM) fiber laser
with tunable wavelength spacing using an all-PM linear cavity that makes use of two reflection peaks from the PM fiber Bragg
grating (PM-FBG). Experimental results show stable dual lasing lines with a wavelength separation of ∼0.22 nm and a large
optical signal-to-noise ratio (OSNR) of over 40 dB under room temperature. By applying axial strain to the PM-FBG, the center
wavelengths of the two lasing lines can be tuned over several nanometers and the wavelength separation between the lasing
lines can also be tuned to as small as 0.05 nm, which, to our knowledge, is the smallest wavelength spacing ever obtained
from a stable room-temperature dual-wavelength fiber laser. The proposed laser configuration has the advantages of simple
structure, low loss, stable dual-wavelength operation and a very small lasing linewidth of ∼5 kHz .
PACS 42.55.Wd; 42.81.-i; 42.81.Gs 相似文献
9.
We experimentally demonstrate a wavelength-spacing tunable multiwavelength erbium-doped fiber laser based on degenerate four-wave mixing in a dispersion-shifted fiber incorporating multiple-fiber Bragg gratings. We have achieved stable operation of the multiwavelength erbium-doped fiber laser, which has 0.8 nm spacing ten-channel lasing wavelengths and a high extinction ratio of more than approximately 45 dB, at room temperature. The output power of the multiwavelength erbium-doped fiber laser is stable, so the peak fluctuation is less than approximately 0.2 dB. By changing the properties such as loss and polarization state of multiple fiber Bragg grating cavities, we can exercise flexible control of the wavelength spacing of the multiwavelength output. We can also obtain switchable multiwavelength lasing operation by elimination of the effects of alternate single-fiber Bragg gratings. 相似文献
10.
Wavelength spacing tunable dual-wavelength single-longitudinal-mode fiber ring laser based on fiber Bragg gratings 总被引:1,自引:0,他引:1
A wavelength spacing tunable dual-wavelength single-longitudinal-mode fiber ring laser is presented by employing separated fiber Bragg gratings. By using a saturable-absorption-induced grating filter and a hybrid gain medium formed by a semiconductor optical amplifier and an erbium-doped fiber amplifier, stable single-longitudinal-mode lasing is achieved at room temperature. Wavelength spacing of the proposed fiber laser can be tuned in a range from 0.1 to 1.3 nm. 相似文献
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A single-mode fiber laser based on an intracavity core-cladding mode conversion is demonstrated. The fiber laser consists of an Er-doped active fiber and two fiber Bragg gratings. One Bragg grating is a core-cladding mode converter, and the other Bragg grating is a narrowband high reflector that selects the lasing wavelength. Coupling a single core mode and a single cladding mode by the grating mode converter, the laser operates as a hybrid single-mode laser. This approach for designing a laser cavity provides a much larger mode area than conventional large-mode-area step-index fibers. 相似文献
12.
Effects of facet reflectivity of a laser diode on the performance of fiber Bragg grating semiconductor lasers are studied experimentally. Facet reflectivity of less than 10-4 is necessary to obtain stable oscillation wavelength. 相似文献
13.
We report an all-fiber actively Q-switched erbium-doped fiber laser, where the linear laser cavity mirrors are composed of two fiber Bragg gratings (FBGs). The laser oscillation wavelength could be tuned by this pair of temperature controlled FBGs. The Q-switching is achieved by an all-fiber phase modulation device. Using this system, we could obtain stable Q-switched laser pulses output, which could be optimized by tuning the reflection wavelengths of the two FBGs to be adjacent to each other. Instead of being modulated by the FBG filter in high-speed oscillation, this fiber laser system is operating in the Q-switched regime using an all-fiber phase modulator, producing a more stable laser output spectrum. 相似文献
14.
J. A. Alvarez-Chavez A. Martínez-Rios I. Torres-Gomez A. Gonzalez-Garcia H. L. Offerhaus 《Laser Physics》2008,18(3):353-356
We report on a wide wavelength tuning in a double-clad ytterbium-doped fiber laser. The laser cavity consists of an array of broadband high-reflection fiber Bragg gratings and a bulk grating as the output coupler and wavelength selection element. The proposed fiber laser configuration combines a low intracavity loss of the fiber Bragg grating mirrors with a wide wavelength tuning of the bulk gratings. We demonstrate a >70-nm wavelength tuning range, limited only by the available fiber Bragg gratings. 相似文献
15.
Zhi-Ming Liu Jian Li Peng Liu Jing-Jing Zheng Lin-Yong Fan Shui-Sheng Jian 《Optics & Laser Technology》2010,42(8):1261-1265
A simple and effective switchable dual-wavelength polarization-maintaining erbium-doped fiber laser is proposed and demonstrated. Only using a uniform fiber Bragg grating written directly in a segment of the photosensitive and polarization-maintaining erbium-doped fiber as the wavelength selector and an optical circulator as the all-reflecting mirror, a stable simultaneous dual-wavelength oscillation is achieved with a wavelength spacing of 0.364 nm experimentally by exploiting the polarization hole burning effect at room temperature. The output can be switched between single- and dual-wavelength by adjusting the polarization controller. The 3-dB bandwidth and the side mode suppression ratio of the laser’s outputs are measured to be less than 0.01 nm and more than 50 dB. The power fluctuation and wavelength drift are measured to be less than 0.50 dB and 0.020 nm over an hour. 相似文献
16.
Goto R Williams RJ Jovanovic N Marshall GD Withford MJ Jackson SD 《Optics letters》2011,36(10):1872-1874
We present a narrow-linewidth, linearly polarized neodymium-doped fiber laser that incorporates a point-by-point Bragg grating inscribed into the core of a single-polarization all-solid photonic bandgap fiber. The Bragg grating was written within a single-polarization wavelength band of the fiber; thus, the Bragg reflection was polarized. This all-fiber laser produced 7.2 W, linearly polarized output with 25 pm FWHM and 19.6 dB polarization extinction ratio. 相似文献
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Xinhuan Feng Lei Sun Yange Liu Lingyun Xiong Shuzhong Yuan Guiyun Kai Xiaoyi Dong 《Optical and Quantum Electronics》2004,36(10):919-926
A simple actively mode-locked fiber ring laser is proposed and successfully demonstrated to generate dual-wavelength picosecond pulses with close wavelength spacing using one Bragg grating in standard single-mode fiber. The proposed laser can be made to operate in stable dual-wavelength at room temperature, due to the birefringence characteristic of the FBG induced by transverse strain. Transverse strain loading on the FBG allows the wavelength spacing to be controlled. Generation of stable dual-wavelength pulses with a pulsewidth of 212–234 ps and a tunable wavelength separation from 0.2 to 0.44 nm at a pulse rate of 1.05 GHz was demonstrated. 相似文献
19.
根据双光纤Bragg光栅(FBG)外腔半导体激光器相干失效的物理过程, 运用速率方程和双FBG耦合模理论, 分析了双FBG外腔半导体激光器相干失效产生和控制的条件, 提出了实现和控制双FBG外腔半导体激光器相干失效多模稳定工作的方法. 双FBG外腔半导体激光器在相干失效下具有多模的稳定工作状态, 相干失效长度缩短, 相干失效长度内光谱稳定. 实验测量结果表明, 外腔反射率为3%时, 从非相干失效状态到相干失效状态, 半峰值全宽度从0.5 nm突然展宽到0.9 nm. 在相干失效状态下, 功率稳定, 边模抑制比大于45 dB, 在0℃–70℃工作温度范围内峰值波长漂移小于0.5 nm, 最小相干失效长度小于0.5 m. 双FBG外腔半导体激光器相干失效的应用对提高光纤放大器和光纤激光器的性能具有重要意义.
关键词:
非线性
半导体激光器
双光纤Bragg光栅
相干失效 相似文献
20.
A novel tunable microwave photonic notch filter using a phase-modulated dual-wavelength fiber laser is presented. A stable dual-wavelength erbium-doped fiber laser with a linear cavity is formed by a polarization-maintaining uniform fiber Bragg grating (PM-FBG) and a polarization maintaining linearly chirped fiber Bragg grating (PM-LCFBG), both of which were fabricated on a high-birefringence (Hi-Bi) fiber. It is found that a stable room-temperature dual-wavelength operation can be achieved due to the presence of two reflection peaks arising from the orthogonal states of polarization (SOP) of the PM-FBG. Experimental results show stable dual-wavelength lasing operation with a wavelength separation of ∼0.36 nm and a large optical signal-to-noise ratio (OSNR) of over 40 dB under room temperature. The dual-wavelength fiber laser is combined with a phase modulator and a segment of single-mode fiber (SMF) as a dispersive device to form a tunable microwave photonic notch filter. By stretching the PM-FBG to tune the wavelength separation of the dual-wavelength fiber laser, a tunable microwave photonic notch filter with various free spectral ranges (FSRs) and a rejection ratio greater than 35 dB was developed. 相似文献