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Wavelength conversion to the wavelength range that is not covered by commercially available lasers could be accomplished through the soliton self-frequency shift (SSFS) effect. In this study, the phenomenon of SSFS pumped by a picosecond-order pulse in a tellurite microstructured fiber is investigated both theoretically and experimentally. The balance between the dispersion and the nonlinearity achieved by a 1958 nm pump laser induces a distinct SSFS effect. Attributed to the large spectral distance between the pump pulse and the fiber zero-dispersion wavelength, the SSFS is not cancelled due to energy shedding from the soliton to the dispersive wave. Details about the physical mechanisms behind this phenomenon and the variations of the wavelength shift, the conversion efficiency are revealed based on numerical simulations. Owing to the large soliton number N, the pulse width of the first split fundamental soliton is approximately 40 fs, producing a pulse compression factor of ∼38, much higher than that pumped by a femtosecond pulse. Experiments were also conducted to confirm the validity of the simulation results. By varying the pump power, a continuous soliton shift from 1990 nm to 2264 nm was generated. The generation of SSFS in tellurite microstructured fibers with picosecond pump pulse can provide a new approach for wavelength conversion in the mid-infrared range and could be useful in medical and some other areas.

We demonstrate a hybrid Brillouin-erbium fiber laser in a composite cavity with a single-mode tellurite fiber. Only a 200 m long tellurite fiber is used in the cavity due to the high effective nonlinearity. The double pass of the tellurite fiber in the linear part is advantageous for improving the Brillouin gain and increasing the comb lines. With a tunable filter, more than 70 comb lines spaced by 7.888 GHz are obtained at 1565 nm. The line number is kept around 60 in the tunable range of 30 nm from 1535 to 1565 nm. Compared with silica fibers, the tellurite fiber can generate a larger number of Brillouin lines in a wider tunable range.

The quasi-CW supercontinuum from 1200 to 2260 nm is demonstrated in a HNLF pumped by the sub-microsecond pulse with the low peak power of 17.8 W. The 20 dB bandwidth of 922 nm is obtained.

A novel cluster-core tellurite microstructured optical fiber which possesses high nonlinearity and supports high-power pumping is presented in this paper. When the light transmits in this fiber, it will be coupled from seven cores into a single one.

We investigate supercontinuum (SC) generation in highly nonlinear tellurite microstructured fibers pumped by a continuous wave (cw)/quasi-cw laser. We investigate two types of tellurite fibers. One type has the constant core diameter, and the other type has a longitudinally varying core diameter. For the fibers with a constant core diameter, when pumped in the anomalous dispersion region, the SC is symmetric in a fiber that has a zero dispersion wavelength close to the pump wavelength. For the fibers with a longitudinally varying diameter, the calculated phase-matching conditions show that they have a broad wavelength range of dispersive waves, and therefore the measured SC spectrum can be broader than one octave. In this work, the fiber lengths are as short as several tens of centimeters, and the pump power is in the watt level.

We demonstrate an all-fiber broadband supercontinuum (SC) source with high efficiency in a single-mode high nonlinear silica fiber. The SC is pumped by the 1557 nm sub-picosecond pulse, which is generated by a homemade passively mode-locked fiber laser, amplified by an EDFA and compressed to 600 fs. The high nonlinear fiber used in experiments has the zero-dispersion wavelength of 1584 nm with low dispersion slope. The pump pulse is in the normal dispersion region and the SC generation is initiated by the SPM effect. When the long-wave band of the spectrum is extended to the anomalous dispersion region, the soliton effects and intra-pulse Raman effects extend the spectrum further. Meanwhile, the dispersive waves shorter than 1100 nm begin to emerge because the phase matching condition is satisfied and the intensity increases with increasing the pump intensity. The broad SC spectrum with the spectral range from 840 to 2390 nm is obtained at the pump peak power of 46.71 kW, and the 10 dB bandwidth from 1120 nm to 2245 nm of the SC covers one octave assuming the peak near 1550 nm is filtered. The temporal trace of the SC has the repetition rate of 16.7 MHz, and some satellite pulses are generated during the nonlinear process. The SC source system is constructed by all-fiber components, which can be fusion spliced together directly with low loss less than 0.1 dB and improves the energy transfer efficiency from the pump source to the SC greatly. The maximum SC average power of 332 mW is obtained for the total spectral range, and the slop efficiency to the pump source is about 70.3%, which will be lower when the peaks near 1550 nm are filtered, but is higher than those in PCFs. The spectral density for the 10 dB bandwidth is in the range from -17.3 to -7.3 dBm/nm.

We report the fabrication of tellurite composite microstructured optical fiber (CMOF) with ultra-flattened zero dispersion (±3 ps/nm/Km) over 200nm band. To obtain this dispersion profile together with high nonlinearity, one ring of air holes and two layers of glass cladding are employed in the tellurite CMOF. The core of fiber is made of TeO 2 -Li 2 O-WO 3 -MoO 3 -Nb 2 O 5 (TLWMN) tellurite glass which possesses high linear and nonlinear refractive indices. The refractive index (n) at 1544nm and nonlinear refractive index (n2) of TLWMN glass is 2.08 and 3.78×10 -11 esu, respectively. TeO 2 -ZnO-Na 2 O-La 2 O 3 (TZNL) glass with n of 1.96 at 1544 nm and TeO 2 -ZnO-Li 2 O-Na 2 O-P 2 O 5 (TZLNP) glass with low refractive index n of 1.63 at 1544 nm are used as the first cladding and the second cladding, respectively. Six small air holes are located between the core and the first glass cladding. Such kind of fiber with ~1.7 μm core and ~0.6 μm air holes are fabricated by a rod-in-tube method. The chromatic dispersion of the fiber is calculated by the fully vectorial finite difference method (FV-FDM) and becomes (±3 ps/nm/Km) in the wide range from 1.53 μm to 1.72 μm. And the nonlinear coefficient of present fiber is about 3.47 m -1 W -1 which is much higher than that of silica MOFs. Furthermore, broad and flattened supercontinuum generation is demonstrated in 30-cm-long fiber with femtosecond laser pumping at 1557 nm. This kind of fiber has promising potential in nonlinear applications owing to the high nonlinearity and flattened dispersion profile.

The microstructured optical fibers have been considered in this paper due to their unique nonlinear properties. These optical fibers have enormous potential and they are also unrestraint to tailor the design for obtaining promising dispersion properties. It has been observed that conversion efficiency significantly increases when nonlinear contribution to propagation constant is considered for phase matching. The phase matching have been obtained for even and higher order dispersion with the optical pump pulse conditions. The coupled mode theory along with nonlinear Schrodinger equation has been used to reveal the optical properties of telluride/phospho-tellurite hybrid microstructured optical fiber. The paper has been focused to investigate the effective index, pulse propagation intensity and quasi phase matching.

We report a detailed implementation of a 2-D finite element method that is applied to calculate the stimulated Brillouin scattering (SBS) characteristics in highly nonlinear tellurite microstructured fibers. Our analysis is firstly made in four air-holes different tellurite microstructured fibers and compared to silica and chalcogenide fibers. Such fibers have drawn much interest because of their capacity of increasing the SBS gain. A Brillouin gain coefficient, gB, of 1 10 -10 m/W is found around the acoustic frequency of 8 GHz. Then, we used real scanning electron microscope images of small core highly nonlinear tellurtie fibers and compared the SBS parameters to numerical predicted results. Good agreement is found between the SBS gain coefficients and the frequency shifts.

Four wave mixing and supercontinuum from tellurite photonic crystal fibers have been widely researched. Their efficiencies depend largely on fiber nonlinearity and chromatic dispersion. We have shown that the composite microstructured optical fibers (CMOFs) can have high flexibility on chromatic dispersion control when refractive index difference between core and cladding becomes larger. Cladding materials with much lower refractive index than tellurite glass are required. We report here a novel tellurite core-phosphate cladding CMOF. Phosphate glasses which thermal expansion coefficient, viscosity, glass transition temperature, deformation and crystallization temperature are close to those of tellurite 78TeO 2 - 5ZnO - 12Li 2 O - 5Bi 2 O 3 (mol%) (TZLB) glass are systematically investigated. The phosphate glass we developed has high transparency and a broad transmission region up to 3 μm as well as a notably low refractive index. Using the phosphate glass doped with mixed alkali oxides obtained in this work, the refractive index difference between core and cladding becomes as high as 0.5 which is sufficiently high to control the chromatic dispersion with high freedom. Our work shows that tellurite-phosphate CMOFs are promising candidates as highly nonlinear fibers with freely controlled chromatic dispersion for nonlinear applications.

We demonstrate passively mode-locked and Q-switched operation in the same fiber laser cavity with normal dispersion. The passively mode-locked pulse works in the stretched-pulse mode-locking mechanism, and the spectrum has smooth and broad rectangular shape. The 3 dB bandwidth of the spectrum increases with the pump power increasing, and it is also changed by the polarization state in the cavity. The obtained maximum 3 dB bandwidth for the pulse is 35.8 nm. The output pulse width is 2.31 ps with high chirp and is dechirped to 210 fs by a standard single-mode fiber, which can be further dechirped to about 110 fs according to the transform-limited time-bandwidth product by compensating the third-order dispersion. The repetition rate of the single pulse operation is 38.3 MHz. With increasing the pump power further, multiple pulses appear and finally six pulses are observed. When the pump power exceeds 180 mW, the mode-locked operation can be switched to the passively Q-switched operation by the polarization state variation. The repetition rate of the Q-switched pulse increases from 162.9 to 348.9 kHz corresponding to the pump powers from 180 mW to 643 mW, and the pulse width decreases from 1122 to 382 ns simultaneously. The Q-switched pulse can be tunable in the spectral range of 8.45 nm from 1558.50 to 1566.95 nm. The operation between the passively mode-locking and the Q-switching can be switched by adjusting the polarization controllers in the cavity.

In this paper, we theoretically investigated the generation of quantum-correlated photon pair through spontaneous four-wave mixing in tellurite microstructured optical fiber. We evaluated the performance of photon pair generation in tellurite fibers based on Raman gain coefficient spectra. It was shown that the TBSN16P6W tellurite fiber provided a low Raman noise on correlation photon generation over a wide pumpidler detuning range. We can choose proper tellurite composition to obtain a low Raman gain window over a wide range for correlated photon pair generation.

We demonstrate theoretically and experimentally that it is feasible to draw the microstructured fiber with longitudinally varying diameter (FLVD) whose diameter varies sharply in a short fiber length. It is elucidated that during the fiber drawing process the tension is linearly proportional to the natural logarithm of the fiber drawing speed. As a result, the tension is not so sensitive to the fiber diameter. Moreover, this sensitivity can be decreased by using a large diameter ratio of preform to fiber. Owing to the low sensitivity the FLVD with diameter varying sharply in a short fiber length can be drawn directly from the preform. Additionally we show that the microstructural geometry of FLVD does not depend on the varying diameter. The deformation in microstructural geometry is determined by the fiber segment with the smallest diameter. We fabricate a FLVD of which the diameter decreases by 75% in a fiber length of 10 cm. By using this fiber we demonstrate the 600-1800 nm supercontinuum (SC) generation and the 532 nm second harmonic generation pumped by a picosecond fiber laser. The SC spectra by the conventional fibers with the largest and the smallest diameters of the FLVD are also shown, respectively. The comparisons show that the FLVD has the broadest SC spectrum due to its high nonlinearity, varying dispersion, and high damage threshold.

We demonstrate a Brillouin-Erbium fiber laser with a single-mode tellurite fiber. 40-line comb is obtained in the tunable range of 37 nm. The average output powers fluctuate in 44-48 mW for the whole tunable range.

The coherent multiple pulses with the number from 2 to 5 are observed in a 1.55 μm normal dispersion cavity. The spectra are highly modulated and the largest pulse separation of 31.9 ps is observed.

We present a numerical investigation on Stimulated Brillouin scattering (SBS) properties in three-core tellurite microstructured optical fiber (MOF). The results show that the SBS in this fiber is much stronger than that in the single-core tellurite MOF.

We present a numerical investigation on the low confinement loss properties of a tellurite hybrid-guiding photonic bandgap fiber with a solid core surrounding byhigh-index rods and air-holes.

The dark pulses are demonstrated in a long ring cavity with single-mode tellurite fiber. The pulse widths of the dark pulses change with the polarization states. The multiple dark pulses are observed by polarization controlling.

We proposed a TBSN16P6W tellurite/phosphate composite microstructured optical fiber with small dispersion value and high nonlinear coefficient at telecommunication wavelengths to realize efficient and low noise quantum-correlated photon pair generation.

For the first time we have investigated supercontinuum (SC) generation by filamentation in tellurite glass. The conical visible emissions were observed. An ultra-broadband SC spectrum covering 690-5700 nm was obtained.

We try to obtain stable supercontinuum (SC) generation with broad bandwidth under relative simple pump conditions. We use a 1.3-m-long highly nonlinear tellurite microstructured fiber and pump it by a 15 ps 1064 nm fiber laser. One segment of the fiber is tapered from a core diameter of 3.4 μm to 1.3 μm. For the first time five-order stimulated Raman scatterings (SRSs) are observed for soft glass fibers. SC covering 730-1700 nm is demonstrated with the pump-pulse-energy of several nJ. The mechanisms of SC broadening are mainly SRS, self-phase modulation (SPM) and cross phase modulation (XPM). The tapered segment has two advantages. Firstly it increases the nonlinearity of fiber by several times. Secondly, it acts as a compensation for the dispersion of the untapered segment, and mitigates the walk-off between pump pulse and SRS peaks.

For a suspended nanowire, the holes surrounding the core are expected to be as large as possible to propagate the light at wavelengths as long as possible. However, the fabrication of nanowire surrounded with large holes is still a challenge so far. In this paper, a method which involves pumping positive pressure of nitrogen gas in both the cane fabrication and fiber-drawing processes, is proposed. A suspended nanowire, with a core diameter of 480 nm and an unprecedented large diameter ratio of holey region to core (DRHC) of at least 62, is fabricated in the length of several hundred meters. Owing to the large holes, the confinement loss of the suspended nanowire is insignificant when the wavelength of light propagated in it is 1700 nm. Additionally, the tube-shaped glass cladding of the suspended nanowire shifts the singlemode cutoff wavelength to 810 nm, which is much shorter than the cutoff wavelength, 1070 nm, of a naked nanowire with the same diameter. A single-mode supercontinuum (SC) generation covering a wavelength range of 900-1600 nm is obtained under 1064 nm pump pulse with the peak power as low as 24 W. A single-mode third harmonic generation (THG) is observed by this nanowire under the pump of a 1557 nm femtosecond fiber laser. This work indicates that the suspended nanowire with large holes can provide high nonlinearity together with single-mode propagation, which leads to interesting applications in compact nonlinear devices.

We propose a tellurite core phosphate cladding composite microstructured optical fiber (MOF) with high nonlinearity and flattened dispersion for parametric amplification. To rea lize flattened dispersion, the structure parameters such as the tellurite core diameter, the air hole diameter and the distance between the centers of the two neighboring air holes are optimized. The ultraflat dispersion curve is obtained for tellurite core of 1.1 m, pitch of 1.2 m and air hole diameter of 0.5 m. In this case, the flattened dispersion with value between -4 and 0.5 ps/nm/km is obtained ranging from 1400 to 1600 nm. The nonlinear coefficient J is as high as 2.5 m -1 W -1 at 1.5 m. The optical parametric gain bandwidth of nearly 200 nm can be achieved in composite tellurite/phospha te MOF with the length of 2.5 m and the pump power of 0.4 W. 1. INTRODUCTION Four-wave mixing (FWM) is one of the basic nonlinear opti cal phenomena observed in opti cal fibers and lead to many applications such as parametric amplification, wavelength conversion, and oscillators

Highly nonlinear fibers have attracted much attention due to their potential applications in many fields, such as pulse compression, supercontinuum (SC) generation and wavelength conversion [1–3]. In order to enhance nonlinear effect, air holes were introduced in microstructured optical fibers (MOFs). Chromatic dispersion which is important for nonlinear processes can also be engineered by air hole design. However, it is known that it is difficult to control the chromatic dispersion of pure tellurite MOFs with high freedom due to its large material dispersion [3]. One solution to overcome this technical issue is to use tellurite composite microstructured optical fiber (CMOF). Figure 1 shows structure of tellurite CMOF designed in this work and its calculated chromatic dispersion. The result indicates the fiber with core diameter (d core ) 1.5 µm, air hole diameter (d hole ) 0.54 µm, pitch 1.21 µm and refractive index difference between core and clad (Δn) 0.1 at 1550 nm, has very flat chromatic dispersion in a wide range near ZDW. We have prepared a novel tellurite CMOF by rod in tube and fiber drawing method for the first time.

We propose a tellurite/phosphate composite microstructured optical fiber with high nonlinear coefficient and flattened dispersion at telecommunication wavelengths to realize efficient parametric frequency conversion and supercontinuum generation.

We demonstrate four-wave mixing based broadband (>68 nm) wavelength conversion and flattened supercontinuum generation spanning from 900 to 2800 nm in a 36-cm long tellurite microstructured fiber which has a high nonlinearity. By reducing the size of air holes of the tellurite microstructured fibers, single mode propagation and small dispersion slope are obtained without the propagation loss enhancement. Our results show that chromatic-dispersion controlled tellurite microstructured fibers are promising candidates for nonlinear applications.

Supercontinuum (SC) generation has the important applications such as broadband light source, optical coherence tomography, ultra-short pulse compression, and optical frequency metrology, etc. Tellurite glass is transparent in the mid-infrared range, and has a higher n 2 than silica glass by at least one order of magnitude. We have fabricated the hexagonally shaped tellurite air-clad fiber with a core diameter of around 1 μm through controlling the temperature field exactly in the process of fiber-drawing. Since the SC generation strongly depends on the chromatic dispersion, which is determined by the microstructure of fiber, it is interesting to investigate and demonstrate such dependence for such a small core fiber in detail. In this work by pumping a positive pressure of nitrogen gas into the holes of preform, we obtained 1 μm core fibers with diameter ratio of holey region to core (DRHC) varied from 3.5 to 20. The dispersion was tailored effectively by the variation of DRHC. Dependences of SC on the microstructure and dispersion were demonstrated. The pump lasers were picosecond and femtosecond fiber lasers. One octave flattened SC generation was obtained for the fibers pumped by 1064 nm picosecond fiber laser with the pulse energy of several hundred pJ. Intense second and third harmonic generations were obtained under the pump of a 1557 nm femtosecond fiber laser. The correlation of dispersion and SC spectra was analyzed. Such tellurite microstructured optical fibers (MOFs) with high nonlinearity and controlled dispersion are significant in nonlinear applications.

We report broad near-infrared soliton source generation in a TeO 2 -Bi 2 O 3 -ZnO-Na 2 O tellurite microstructured optical fiber pumped by a 1557 nm femtosecond fiber laser. A continuous soliton wavelength shift from 1582 nm to 1851 nm was realized through a tellurite microstructured optical fiber as short as 6.5 cm. Experimental results are in good agreement with the numerical simulations using a generalized nonlinear Schrodinger equation. In addition, an analytical description of the Raman response function of tellurite glass is provided, and a Raman contribution factor of 0.51 is obtained from the actual Raman gain spectrum.

We propose a defected core tellurite/phosphate composite microstructured fiber with four zero dispersion points which creates a rich phase-matching topology. The great enhanced flexibility in the positioning has applications in four wave mixing.

Novel tellurite microstructured fibers are developed with new potentials of dispersion engineering for mid-infrared supercontinuum generation. We demonstrate low threshold single-mode supercontinuum by using a nanowire and present a new prospect of tellurite MOFs.

We demonstrate visible light generation in chalcogenide As2S3 microstructured optical fiber. The generated visible light causes irreversible damage to the fiber core because of the high absorption coefficient of chalcogenide glasses in the visible band. The SCs (supercontinua) are measured in both untapered and tapered As2S3 fibers, no wider SC is obtained in the tapered one. The SC growth is prevented by the visible light generation since the damage to the fiber core decreases the fiber transmission substantially. This effect can be avoided by designing the fiber to enable the pump source to work in single-mode operation.

We prepared a novel composite tellurite MOFs consisting of two different glasses as core and clad to freely control chromatic dispersion. Broad and flattened SC spectra were demonstrated in the fiber under femtosecond laser pumping.

A tellurite suspended core nanofiber with extremely large holey region is demonstrated for the first time. A single-mode third harmonic generation is observed under the 1557 nm pump by a femtosecond fiber laser.

We demonstrate visible light generation in As 2 S 3 microstructured fiber for the first time. It limits the spectral range of supercontinuum. The visible light generation can be avoided by designing the fiber for the single-mode operation.

Enhanced soliton trapping of dispersive waves in a tapered tellurite microstructured fiber pumped by a 1557 nm femtosecond laser is demonstrated. The short wavelength edge of supercontinuum light is extended from 960 to 600 nm.

An analytical description of the Raman response function of tellurite fiber is provided. The Raman contribution factor f R of 0.51 and Raman time constant of 8.07 fs are obtained from the Raman gain spectrum.

Tellurite air-clad fibers with small hexagonal core and controlled dispersion were fabricated. Dependences of supercontinuum generation, pumped by picosecond pulse, on the microstructure and dispersion of these fibers were demonstrated for the first time.

We report what we believe to be the first demonstration of the second and third harmonics in tellurite microstructured fibers pumped by a 1557 nm femtosecond fiber laser. The intensities of the second and third harmonics are enhanced by increasing the nonlinear coefficient of the tellurite microstructured fiber. By using tellurite microstructured fiber with a core diameter of approximately 2.7 microm, supercontinuum light expanding from 470 nm to 2400 nm could be achieved. The effects of the fiber-core diameter on the flatness of the supercontinuum light are also investigated when pumped at 1557 nm.

For a suspended core nanofiber, the holey region is expected to be as large as possible to propagate the light at wavelengths as long as possible. Additionally, a large holey region is significant for its applications in sensors. However, the fabrication of nanofiber with large holey region is still a challenge so far. In this paper a method, which involves pumping positive pressure of nitrogen gas in both the cane fabrication and fiber-drawing processes, was proposed. A suspended core nanofiber, with a core diameter of around 480 nm and an unprecedented diameter ratio of holey region to core (DRHC) of at least 62, was fabricated in the length of several hundred meters. Owing to the large holey region, the confinement loss of the suspended core nanofiber is insignificant when the wavelength of light propagated in it is 1700 nm. For this fabrication technique, the nanowire length, fabrication efficiency, and the uniformity in the diameter are much superior to those of the nanowires fabricated in other ways. Finally, single mode third harmonic generation was observed by this nanofiber under the pump of a 1557 nm femtosecond fiber laser. This work shows the prospect of fabrication of nanostructured waveguide in glass materials by an inflation technique.

Tellurite highly nonlinear microstructured fibers were fabricated by pumping a positive pressure of nitrogen gas into the holes of cane in the fiber drawing process. By adjusting the pump pressure to inflate the holes of the fiber, the microstructures were reshaped, and the chromatic dispersions were tailored. Two kinds of fiber were fabricated. One is an air-clad fiber with a 1 μm hexagonal core, which is the smallest core in this shape for the air-clad fiber. By changing the inflation pressure, the diameter ratio of holey region to core (DRHC) was changed in the range of 1-20. Fibers with DRHC of 3.5, 10, 20 were demonstrated. By increasing the DRHC, the zero dispersion wavelengths were shifted to the short wavelength and the confinement loss were decreased. Another is a complex microstructure fiber with a 1.8 μm core surrounded by four ring holes. The shape of the microstructure was reshaped so heavily by the inflation pressure that it is obviously different from the original shape in the cane. The correlations among pump pressure, hole size, surface tension and temperature gradient were investigated. The temperature gradient at the bottom of the preform's neck region was evaluated quantitatively. The chromatic dispersion of this fiber was compared with that of a step-index air-clad fiber. It was found that this fiber had a much more flattened chromatic dispersion. Supercontinuum generations were investigated by the pump of a 1557 nm femtosecond fiber laser. Intense third harmonic generations were obtained from the 1μm haxgonal core fiber. Broad and flattened spectrum was obtained from the complex microstructure fiber. This investigations show that, by using a positive pressure to reshape the microstructure and by controlling the fabrication conditions exactly, highly nonlinear soft glass fibers with desirable chromatic dispersion can be fabricated, and such fibers have interesting applications in highly nonlinear field such as THG and SC generation.

We propose a chalcogenide (As 2 S 3 ) core tellurite cladding microstructured fiber with flattened normal dispersion for ultraflat supercontinuum (SC) generation. To realize flattened normal dispersion, the structure parameters are optimized such as the chalcogenide core diameter, the air hole diameter and the distance between the centers of the two neighboring air holes. The ultraflat normal dispersion curve is obtained and the pulse propagation is investigated using a nonlinear Schrodinger equation. It is shown that an ultraflat SC spectrum with deviations less than 4 dB over an octave (from 1400 nm to 3000 nm) can be achieved by the illumination of a pulsed light with a pulse width of 200 fs, central wavelength of 2000 nm and peak power of 1000 W.

We demonstrate wide and flattened supercontinuum generation in zero-dispersion wavelength decreasing tellurite microstructured fibers fabricated by using the tapering method.

We demonstrate ultra-broadband SC generation from UV to 6.28 μm in a 2-cm-long fluoride fiber pumped by a 1450 nm femtosecond laser. ©2010 Optical Society of America.

We demonstrate widely tunable narrowband soliton and dispersive wave source generation (1150-2250 nm) in a highly nonlinear tellurite microstructured fiber pumped by a 1550 nm femtosecond fiber laser.

We shows new potential of tellurite fibers with high nonlinearity as optical signal processing and coherent light generation media by demonstrating applications of stimulated Raman and Brillouin scattering and supercontinuum generation.

A highly nonlinear composite fiber, which has a 1.5 microm chalcogenide glass core surrounded by a tellurite glass microstructure cladding, has been fabricated by the method of stack and draw. A tellurite glass capillary containing a As(2)S(3) rod was sealed with negative pressure inside. Then this capillary and other empty capillaries were stacked into a tellurite glass tube, and elongated into a cane. This cane was then inserted into another tellurite glass jacket tube and drawn into the composite microstructure fiber. The fiber has a flattened chromatic dispersion together with a zero dispersion wavelength located in the near infrared range. The propagation losses at 1.55 microm were 18.3 dB/m. The nonlinear coefficient at 1.55 microm was 9.3 m(-1)W(-1). Such a high nonlinear coefficient counteracts the high propagation losses to a large extent. A supercontinuum spectrum of 20-dB bandwidth covering 800-2400 nm was generated by this composite microstructure fiber.

We demonstrate widely tunable green (528∼542 nm) third harmonics and near infrared (1228∼1867 nm) soliton (or dispersive wave) source generation in tellurite microstructure fibers.

We report what we believe to be the first demonstration of the second, third harmonics and flattened supercontinuum generation in tellurite microstructure fibers pumped by a 1557 nm femtosecond fiber laser.

Tellurite glass microstructure fibers with a 1 microm hexagonal core were fabricated successfully by accurately controlling the temperature field in the fiber-drawing process. The diameter ratio of holey region to core (DRHC) for the fiber can be adjusted freely in the range of 1-20 by pumping a positive pressure into the holes when drawing fiber, which provides much freedom in engineering the chromatic dispersion. With the increase of DRHC from 3.5 to 20, the zero dispersion wavelengths were shifted several hundred nanometers, the cutoff wavelength due to confinement loss was increased from 1600 nm to 3800 nm, and the nonlinear coefficient gamma was increased from 3.9 to 5.7 W(-1)/m. Efficient visible emissions due to third harmonic generation were found for fibers with a DRHC of 10 and 20 under the 1557 nm pump of a femtosecond fiber laser. One octave flattened supercontinuum spectrum was generated from fibers with a DRHC of 3.5, 10 and 20 by the 1064 nm pump of a picosecond fiber laser. To the best of our knowledge, we have for the first time fabricated a hexagonal core fiber by soft glass with such a small core size, and have demonstrated a large influence of the holey region on the dispersion, nonlinear coefficient and supercontinuum generation for such fiber.

Tellurite glasses are known as one of highly nonlinear fiber materials. We shows new potential of tellurite fibers as lightwave signal processing media by demonstrating applications of stimulated Raman and Brillouin scattering, and supercontinuum generation.