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1.
A broadband continuum generation is reported in a novel multicore microstructured optical fiber (MOF) where irregular air holes are randomly distributed in cladding. By launching ultrashort light pulses from a Ti:sapphire laser into a 190-mm-long fiber of this type, we have observed a group of continua generated from different cores, each with distinct color. 20-dB bandwidth of the broadest continuum is 1260 nm with an average power of 143 mW. The result confirms that the multicore MOF can be fabricated, with different dispersion profiles tailored for specific supercontinuum (SC) generation towards practical applications.  相似文献   

2.
Picosecond pulse pumped supercontinuum generation in photonic crystal fiber is investigated by performing a series of comparative experiments. The main purpose is to investigate the supercontinuum generation processes excited by a given pump source through the experimental study of some specific fibers. A 20-W all-fiber picosecond master oscillator-power amplifier (MOPA) laser is used to pump three different kinds of photonic crystal fibers for supercontinuum generation. Three diverse supercontinuum formation processes are observed to correspond to photonie crystal fibers with distinct dis- persion properties. The experimental results are consistent with the relevant theoretical results. Based on the above analyses, a watt-level broadband white light supercontinuum source spanning from 500 nm to beyond 1700 nm is demonstrated by using a picosecond fiber laser in combination with the matched photonic crystal fiber. The limitation of the group velocity matching curve of the photonic crystal fiber is also discussed in the paper.  相似文献   

3.
We experimentally investigate the high-order harmonic generation in argon gas cell driven by a multi-cycle broadband infrared laser pulse from a tunable optical-parametric-amplifier (OPA) source. The generation of high-order harmonic continuum with the cut-off photon energy up to 110 eV is observed by tuning the chirp of the 800-nm laser pulse which pumps OPA source. The generation of harmonic continuum is understood in terms of the two-hump structure of the OPA output spectrum and the optimal relative phase of the two humps. The demonstrated scheme is of importance for the generation of extreme ultraviolet (XUV) continuum at higher photon energy region.  相似文献   

4.
In this paper, the generation of dual-wavelength stable nanosecond pulses by a laser diode pumped Yb-doped double-clad fiber laser is presented. In the experiment, the fiber laser with two-mirror cavity is approved which operates in a self-Q-switching regime. The Q-switching mechanism is based on stimulated Brillouin scattering (SBS). When the pump power achieves the SBS threshold, the fiber laser changes from the start resonator to the SBS resonator. With different reflectivities of the second mirror, stable dual-wavelength pulses with the pulse width range from 10 ns to less than 2 ns are obtained. The result was explained theoretically by birefringency (including stochastic birefringency and bend birefringency).  相似文献   

5.
We report supercontinuum (SC) generation in a lead silicate SF57 photonic crystal fiber by using a 1550 nm pump source. The effective nonlinear coefficient of the SF57 fiber is simulated to be 111.5 W-1 ·km-1 at 1550 nm. The fiber also shows ultraflat dispersion from 1700 nm to 2100 nm. Our results reveal that with an increase of the average power of the incident pulse from 10 mW to 90 mW, the SC of the SF57 photonic crystal fiber is generated from 1300 nm to 1900 nm with high stability and without significant change in spectral broadening.  相似文献   

6.
Supercontinuum Generation in a Photonic Crystal Fibre   总被引:4,自引:0,他引:4       下载免费PDF全文
Nearly 1000-nm broad continuum from 390 nm to 1370 nm is generated in a 2-m long photonic crystal fibre. The maximum total power of supercontinuum is measured to be 60mW with the pumping power of 800mW output from a 200-fs Ti:sapphire laser. The evolution of the pumping light into supercontinuum is experimentally studied in detail. It is found that the mechanism for supercontinuum generation has direct relations with Raman effect and soliton effect, and the four-wave mixing plays an important role in the last phase of the supercontinuum generation.  相似文献   

7.
We demonstrate a Q-switched Raman fiber laser using molybdenum disulfide(MoS_2) as a saturable absorber(SA).The SA is assembled by depositing a mechanically exfoliated MoS_2 onto a fiber ferrule facet before it is matched with another clean ferrule via a connector.It is inserted in a Raman fiber laser cavity with a total cavity length of about 8 km to generate a Q-switching pulse train operating at 1560.2 nm.A 7.7-km-long dispersion compensating fiber with 584 ps·nm~(-1)km~(-1) of dispersion is used as a nonlinear gain medium.As the pump power is increased from 395 mW to 422 mW,the repetition rate of the Q-switching pulses can be increased from 132.7 to137.4kHz while the pulse width is concurrently decreased from 3.35μs to 3.03μs.The maximum pulse energy of 54.3nJ is obtained at the maximum pump power of 422 mW.These results show that the mechanically exfoliated MoS_2 SA has a great potential to be used for puise generation in Raman fiber laser systems.  相似文献   

8.
A new method to achieve 2-μm pulsed fiber lasers based on a supercontinuum(SC) is demonstrated. The incident pump light is a pulsed SC which contains a pump light and a signal light at the same time. The initial signal of the seed laser is provided by the incident pump light and amplified in the cavity. Based on this, we obtain a 2-μm pulsed laser with pulse repetition rate of 50 kHz and pulse width of 2 ns from the Tm-doped fiber laser. This 2-μm pulsed laser is amplified by two stages of fiber amplifiers, then the amplified laser is used for mid-infrared(mid-IR) SC generation in a 10-m length of ZrF4–BaF2–LaF3–AlF3–NaF(ZBLAN) fiber. An all-fiber-integrated mid-IR SC with spectrum ranging from 1.8 μm to4.3 μm is achieved. The maximal average output power of the mid-IR SC from the ZBLAN fiber is 1.24 W(average output power beyond 2.5 μm is 340 mW), corresponding to an output efficiency of 6.6% with respect to the 790-nm pump power.  相似文献   

9.
Frequency-tunable microwave signal generation is proposed and experimentally demonstrated with a dual-wavelength single-longitudinal-mode (SLM) erbium-doped fiber ring laser based on a digital Opto-DMD processor and four-wave mixing (FWM) in a high-nonlinear photonic crystal fiber (PCF). The high-nonlinear PCF is employed for the generation of the FWM to obtain stable and uniform dual-wavelength oscillation. Two different short passive sub-ring cavities in the main ring cavity serve as mode filters to make SLM lasing. The two lasing wavelengths are electronically selected by loading different gratings on the Opto-DMD processor controlled with a computer. The wavelength spacing can be smartly adjusted from 0.165 nm to 1.08 nm within a tuning accuracy of 0.055 nm. Two microwave signals at 17.23 GHz and 27.47 GHz are achieved. The stability of the microwave signal is discussed. The system has the ability to generate a 137.36-GHz photonic millimeter signal at room temperature.  相似文献   

10.
A modified large-eddy simulation model,the dynamic coherent eddy model(DCEM)is employed to simulate the generation and propagation of internal solitary waves(ISWs)of both depression and elevation type,with wave amplitudes ranging from small,medium to large scales.The simulation results agree well with the existing experimental data.The generation process of ISWs is successfully captured by the DCEM method.Shear instabilities and diapycnal mixing in the initial wave generation phase are observed.The dissipation rate is not equal at different locations of an ISW.ISW-induced velocity field is analyzed in the present study.The structure of the bottom boundary layer(BBL)of internal wave packets is found to be different from that of a single ISW.A reverse boundary jet instead of a separation bubble exists behind the leading internal wave while separation bubbles appear in other parts of the wave-induced velocity field.The boundary jet flow resulting from the adverse pressure gradients has distinctive dynamics compared with free shear jets.  相似文献   

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