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Passively mode-locked fiber lasers (PML-FLs) are versatile sources that are capable of generating a broad variety of short and ultrashort optical pulses. Besides conservative solitons, PML-FLs allow the generation of different kinds of dissipative structures, usually called dissipative solitons, a concept that also encompasses more complex structures and collective behaviors such as soliton molecules, gas, rain of solitons, etc. In addition to this, PML-FLs are also able to generate even more complex objects, the so-called noise-like pulses (NLPs). A few recent research results revealed a connection between NLPs and solitons, a sign that deterministic ingredients enter into the composition of NLPs, whose nature is traditionally assumed to be random. Although it is usual that a fiber laser is able to generate either solitons or noise-like pulses, depending on pump power and adjustments in the cavity, these two regimes are rarely observed simultaneously. In this paper, a PML-FL in a ring configuration is presented, in which it is possible to observe and verify experimentally the simultaneous presence of NLPs and solitons. Interestingly, these two components are found in different spectral regions, which greatly facilitates their separation and individual study and characterization.

We show the sensing of load by means mechanically induced long-period fiber grating (MLPFG) made by applying pressure by means a screw to a pair of grooved plates over single-mode fiber. We used a torquemeter in order to obtain precision in the adjustment screw and thus establish an equilibrium pressure applied to a specific region of the optical fiber to form the long-period grating mechanically induced fiber. The increase the torque to screw, the resonance wavelength of MLPFG increases its depth over 16 dB. We use a detector to observe the changes amplitude according to the fiber pressure.

Here we propose a simple design for a solid-core photonic crystal fiber made of silica by keeping the golden ratio (1.618) between pitch and air hole diameter Λ /d in a subset of six rings of air-holes with hexagonal arrangement. In the case when we have a pitch equal to one micron (Λ =1 μm), we need air-holes diameters d=0.618 μm in order to obtain the golden ratio parameter (Λ/d=1.618), and achieve two zero dispersion wavelength (ZDW) points at 725 nm and 1055 nm; this gives us the possibility to use this fiber in supercontinuum generation using a laser emission close to that points. We analyzed a series of fibers using this relation and show the possibilities of tunable ZDW in a wide range of wavelengths from 725 nm to 2000 nm with low losses and small effective area. In agreement with the ZDW point needed, the geometry of the structure can be modified to the point of having only three rings of air holes that surround the solid core with low losses and good confinement mode. The design proposed here is analyzed using the finite element method (FEM) with perfectly matched layers (PML), including the material dispersion directly into the model applying the Sellmeier’s equation.

Previous measurements of electron emission by cw laser-irradiated tungsten needles have been extended to pulsed laser irradiation using a 7-ns long, doubled Nd : YAG laser at intensities up to 10 11 W/m 2 . The results show that the mechanism for emission changes from the tunnelling mechanism observed in the cw case, characterized by exponential voltage dependence, to an ablative mechanism characterized by very weak voltage dependence. The observed emission has a threshold around 10 11 W/m 2 , just below the damage threshold for the needles. Using needles with a 1-mm tip radius at voltages up to 50 kV, current densities as high as 10 11 A/m 2 were observed. r 2001 Published by Elsevier Science B.V. PACS: 41.75.Fr; 79.70.+q; 79.60.� i

Experiments have been carried out at laser intensities of the order of 108 W/m2 using a cw argon laser and tungsten needles with roughly 1-μm tip radius operated at voltages up to 50 kV. The results show a nonlinear dependence of the photocurrent on the laser intensity and a strong dependence of the photocurrent on the electric field. Comparison with theoretical calculations based on the Fowler–Nordheim tunneling theory of field emission indicates that the photoexcited electrons rapidly relax to energy levels just above the Fermi level, from which they tunnel out.

A compact high temperature fiber sensor where the sensor head consists of a short fattened long period fiber grating (F-LPFG) of at least 2 mm in length and background loss of −5 dBm is reported. On purpose two different F-LPFGs were used to measure temperature variations, taking advantage of their broad spectrum and the slope characteristics of the erbium light source. This approach affected the spectrum gain as the linear band shifting took place. The measured sensitivity of the long period fiber gratings were about 72 pm/°C in a range from 25 to 500 °C. Here, the temperature rate of the experiment was 0.17 °C/s and the temperature response time was within 3 s. Moreover, temperature changes were detected with an InGaAs photodetector, where a sensitivity of 0.05 mV/°C was achieved.

We propose the use of a figure eight fiber laser cavity in fundamental and harmonic mode-locking noise-like pulsing regimes, with output pulse energies as high as 302.8 nJ, as an improved supercontinuum source. The absence of a polarizer in the laser setup, so that the state of polarization along the cavity is not restricted, allows enhanced performances compared to other similar schemes. Noise-like pulses with durations of a few tens of ns were generated and a coherence length in the order of ps. For proper adjustments, self-starting passive mode-locking is obtained and a supercontinuum spectrum is observed at the laser output. We observe that the spectrum flatness is significantly improved in the harmonic mode-locking regime of the fiber laser. These results were achieved without the need to insert any high-nonlinearity propagation medium in the setup or at the laser output.

In this experimental paper, a multi-wavelength erbium-doped ring fiber laser based on an all fiber intrinsic Fabry–Perot interferometer is presented and demonstrated. The interferometer was fabricated by an arc and splicing technique using hollow core photonic crystal fiber (HCPCF) and conventional single mode fiber (SMF28). The fiber laser can be operated in single, dual and triple lasing mode by applying a transversal load over the all fiber interferometer. The laser spectrums present minimal mode spacing of 1 nm, high wavelength stability and power fluctuations around 0.5 dB. The average signal to noise ratio (SNR) of the laser emissions spectrum is around 35 dB. This fiber laser offers low cost, compactness and high wavelength stability.

We report on the dynamics of noise-like pulses at the ns scale in a passively mode-locked fibre laser, which grow in complexity as wave retarder adjustments are performed. We can observe that the laser operating in the fundamental mode can be tuned to get different shapes of the noise-like pulse. Following a regime of a very stable waveform, regimes characterized by a much more variable (but still compact) waveform are observed. Then we can get the fragmentation of the main bunch and expulsion of sub-packets and, finally, a variety of puzzling dynamics with increasing complexity are evidenced. Although the collective behaviour of the multiple waveforms is at first sight random we can observe some well-defined patterns in the kinematics of light bunches at the global cavity scale. These results may be useful to unravel the subtle mechanisms at play in complex dissipative nonlinear systems such as passively mode-locked fibre lasers.

In this paper we shows the results obtained to fabricate and implement Mach-Zehnder interferometers of conventional fiber optic using Long Period Fiber Gratings (LPFG´s) which were developed by electric arc technique. We obtains this type of interferometer when we fabricated two LPFG’s in series or in cascade with the same characteristics such as number of discharges and the same period, placing them in cascade separated by a distance which three times the length of the LPFG. The application which was given at interferometer fabricated was as a liquids sensor, volume sensor of liquids and micro-displacement sensor. The sensors of liquids and liquids volumes were placed in a container in which the interferometer is fixed so that results of measurements are only by incorporating each of the liquid and not by some external movement. The sensed fluids were: water, alcohol and solution (water with sugar). Final length of the interferometer is between 4 to 6 cm. We analyze the results obtained to when a section the Mach-Zehnder interferometer is displaced in of the order of microns. The variations observed in transmission spectra obtained from each of the sensors mentioned, show changes in the amplitude and the attenuation peak of the interferometer was displaced.

We study numerically and experimentally multiple-wavelength operation of an erbium-doped figure-eight fiber laser including a multiple-bandpass optical filter formed by two concatenated fiber tapers. Both continuous-wave and pulsed operations are considered. In the continuous-wave regime, stable long-term operation at multiple closely spaced wavelengths is only obtained if fine adjustments of the cavity losses are performed. Under these conditions, simultaneous lasing at up to four wavelengths separated by 1.5 nm was observed experimentally. Tunable single-wavelength operation over more than 20 nm is also observed in the continuous-wave regime. In the passive mode locking regime, numerical simulations indicate that mechanisms involving the filter losses and the nonlinear transmission characteristic of the NOLM contribute in principle to stabilize dual-wavelength operation, allowing less demanding cavity loss adjustments. In this regime, the problem of synchronization between the pulse trains generated at each wavelength adds an additional dimension to the problem. In presence of cavity dispersion, the pulses at each wavelength tend to be asynchronous if the wavelength separation is large, however they can be synchronous in the case of closely spaced wavelengths, if cross-phase modulation is able to compensate for the dispersion-induced walkoff. Experimentally, fundamental and 2nd-order harmonic mode locking was observed, characterized by the generation of noise-like pulses. Finally, a regime of multi-wavelength passive Q-switching was also observed. We believe that this work will be helpful to guide the design of multiple-wavelength fiber laser sources, which are attractive for a wide range of applications including Wavelength Division Multiplexing transmissions, signal processing and sensing.

Fiber Gratings are found among the most popular devices widely used in both, optical communications and optical fiber sensing. Within optical communication networks, optical fiber-based devices perform critical operations such as coupling/splitting, wavelengthselective filtering, and optical switching (Han, Y. G. et al., 2004; An H. et al., 2004; Eggleton B. J. et al., 1997). In the field of optical sensing, optical fiber sensors, with unique advantages such as immunity to electromagnetic interference, high sensitivity, resistance to corrosion, and high temperature survivability, are widely used to measure various physical variables such as stress, temperature, pressure, refractive index, etc. and chemical parameters (Udd, E. 1991).

We reported Supercontinuum (SC) generation in standard telecom fiber using picosecond pulses of microchip laser. The pulses width is 700 ps at 1064 nm, using 57 m long of standard fiber, and the spectra extend from 700 to above 1700 nm, some 100 nm further into the visible. The physical processes leading to the formation of the continuum spectrum were studied by monitoring the growth of the SC while increasing the input power. The coupling efficiency of ours experimental setup between the microchip laser and the telecom fiber helped us to obtain this wide spectrum.

This article presents the fabrication of Long Period Gratings in Optical Fiber (LPFGs) applied to the sensing loops. In implementing the manufacturing method used a commercial splicer fiber optic (FiTel S-175), capable of being programmed to a short section of standard optical fiber (SMF28) is taken at intervals between shots in a range from 400µm to of 650µm. The LPFGs Being able to obtain through attenuation bands above 20 dB, while the wavelength of central attenuation is close to 1550nm. We shows the experimental scheme to measure curvatures with diameters ranging between 12 and 13.1cm, having a linear variation of peak output cut at the LPFGs with tuning of 17nm.

In this work we study experimentally and numerically a passively mode-locked figure-eight fiber laser that includes a polarization-imbalanced Nonlinear Optical Loop Mirror (NOLM), whose switching power can be adjusted through a wave retarder plate. The laser emits broadband noise-like pulses with a bandwidth that can exceed 50 nm. The pulses are actually sub-nanosecond wave packets with an inner fine structure of sub-ps pulses with random amplitude and duration. The duration of the pulses as well as their spectral width can be adjusted through the variation of the NOLM switching power. Numerical simulations are in good agreement with experimental results, confirming in particular the strong dependence of the pulse properties on the value of the NOLM switching power, although NOLM switching alone does not explain the appearance of the noise-like pulsing mode. The properties of this kind of pulses, like their wide bandwidth and energy, make them attractive for applications like supercontinuum generation and metrology.

In this work we study experimentally a novel passively mode-locked erbium-doped figure-eight fiber laser based on a polarization-imbalanced Nonlinear Optical Loop Mirror (NOLM). The NOLM operation strongly depends on the polarization state at its input. In this experiment, the input polarization state is set to linear, and its orientation is controlled through a half-wave retarder plate. The variation of the input polarization angle allows adjusting the NOLM switching power over a wide range. In this work we show experimentally that this adjustment makes it possible to tune the spectral bandwidth and the temporal properties of the generated pulses over a wide range.

In this paper we show numerically how a Gires-Tournois etalons (DGTE) is used to flatten the gain spectrum of an erbium-doped fiber amplifier. A broadband amplifier with uniform gain over 40-nm with a residual gain

We propose and study experimentally a novel passively mode-locked figure-eight fiber laser scheme based on a polarization-imbalanced Nonlinear Optical Loop Mirror (NOLM). In contrast to conventional power-imbalanced structures, the NOLM used in the proposed laser relies on a difference of nonlinear polarization rotation between the counter-propagating beams to provide switching. In this experiment, the polarization state at the NOLM input is set to linear. By controlling the polarization orientation at the NOLM input through a half-wave retarder plate, it is possible to adjust the NOLM switching power. This property of the NOLM is attractive in the frame of a figure-eight laser. Firstly, the switching power can be readily set to a value ensuring stable mode-locking operation, without having to cut into the loop and modify the NOLM length. On the other hand, we observed that stable pulsed operation is maintained over a certain range of the NOLM input polarization angle, whereas the pulse properties vary over that range. In particular, the spectral width varies from 16 to 52 nm over that range. This spectral variation is associated with a variation of the pulse temporal properties. This result can be explained by the fact that the input polarization angle allows controlling the critical power of the NOLM, which in turn affects the pulses characteristics. The proposed device thus offers a convenient way to adjust the pulses properties (in particular their spectral bandwidth and duration), simply by controlling the angle of a wave retarder, a property which is attractive for some applications.

DC high voltage photoemission electron guns with GaAs photocathodes have been used to produce polarized electron beams for nuclear physics experiments for about 3 decades with great success. In the late 1990s, Jefferson Lab adopted this gun technology for a free electron laser (FEL), but to assist with high bunch charge operation, considerably higher bias voltage is required compared to the photoguns used at the Jefferson Lab Continuous Electron Beam Accelerator Facility. The FEL gun has been conditioned above 400 kV several times, albeit encountering non‐trivial challenges with ceramic insulators and field emission from electrodes. Recently, high voltage processing with krypton gas was employed to process very stubborn field emitters. This work presents a summary of the high voltage techniques used to high voltage condition the Jefferson Lab FEL photoemission gun.

In this paper we propose a high voltage source which is controlled by a communication port I/O of a data acquisition card. The graphical programming language LabView is employed for this task. We make use of this source to produce optical fiber gratings by inducing an electric arc with the point by point procedure. It has a control section to modify the arc duration time and thus the voltage and current applied to the fiber by means of two electrodes. The experimental setup by which we characterized the gratings is depicted and we also present the transmitting spectrum. The gratings were fabricated with SMF-28 fiber but microstructured fiber can be exploited too. These gratings can be used with optical fiber lasers as optical filters and in the implementation of optical sensors.

We report an original noise-like pulse dynamics observed in a figure-eight fiber laser, in which fragments are continually released from a main waveform that circulates in the cavity. Particularly, we report two representative cases of the dynamics: in the first case the released fragments drift away from the main bunch and decay over a fraction of the round-trip time, and then vanish suddenly; in the second case, the sub-packets drift without decaying over the complete cavity round-trip time, until they eventually merge again with the main waveform. The most intriguing result is that these fragments, as well as the main waveform, are formed of units with sub-ns duration and roughly the same energy.

We report an experimental study of the noise-like pulses generated by a ~300 m long passively mode-locked erbium-doped figure-eight fibre laser. Non-self-starting mode locking yields the formation of ns scale bunches of sub-ps pulses. Depending on birefringence adjustments, noise-like pulses with a variety of temporal profiles and optical spectra are obtained. In particular, for some adjustments the Raman-enhanced spectrum reaches a 10 dB bandwidth of ~130 nm. For the first time to our knowledge, we extract information on the inner structure of the noise-like pulses, using a birefringent Sagnac interferometer as a spectral filter and a nonlinear optical loop mirror as an intensity filter. In particular we show that the different spectral components of the bunch are homogeneously distributed within the temporal envelope of the bunch, whereas the amplitude and/or the density of the sub-pulses present substantial variations along the envelope. In some cases, the analysis reveals the existence of an intermediate level of organization in the structure of the noise-like pulse, between the ns bunch and the sub-ps inner pulses, suggesting that these objects may be even more complex than previously recognized.

In this letter, the effects of bending losses for the development of tunable supercontinuum sources are numerically and experimentally analyzed. Here, the proposed supercontinuum source is based on a very short length segment of standard single-mode fiber (SMF-28) which was used as a nonlinear medium and it was pumped by a microchip Q-switch laser at 1064 nm. In the experimental setup, a section of the optical fiber was wrapped around a mandrel in order to induce bending losses. In addition, by changing the fiber wrapping settings of the SMF-28 the SC source spectrum was filtered at some wavelengths due to mechanical stress. Hence, the source bandwidth can be increased or decreased by selecting the fiber length and by modifying the wrapping settings. Furthermore, in this work it is described as a numerical analysis which helps to support our experimental results. This numerical analysis was based on the fourth-order Runge–Kutta in the interaction picture method and the beam propagation method.

An actively Q-switched double-wavelength Er/Yb fiber laser is experimentally demonstrated. The linear cavity is formed by a pair of fiber Bragg gratings on one side and a Sagnac interferometer (SI) with high birefringence fiber in the loop on the opposite side. A 3 m of double-cladding Er/Yb-doped fiber used as a gain medium is pumped by a 978 nm laser diode. The SI is used to adjust the internal cavity losses for simultaneous dual-wavelength laser generation. The adjustment is performed by temperature variations of the high birefringence fiber in the SI loop. The maximum average output power for the Q-switched laser operation in dual-wavelength mode was around 68 mW with a repetition rate of 40 kHz for 2 W of pump power. The minimum pulse duration was around 280 ns. The maximum pulse energy was 1.75 µJ.

A key technology issue of energy recovery linac (ERL) devices for high-power free-electron laser (FEL) and fourth generation light sources is the demonstration of reliable, high-brightness, high-power injector operation. Three ongoing programs that target up to 0.5 Ampere photocathode injector performance with required ERL brightness, are described. The first is a DC gun and superconducting RF (SRF) booster cryomodule. Such a 748.5 MHz device is being assembled and will be tested up to 100 mA at the Thomas Jefferson National Accelerator Facility (JLAB) beginning in 2006. The second approach is a high-current normal-conducting RF (NCRF) injector. A 700 MHz gun will undergo thermal test in late 2005 at the Los Alamos National Laboratory (LANL), which when equipped with a suitable cathode, would be capable of exceeding 0.5 Ampere operation. Finally, a half-cell 703.75 MHz SRF gun with a diamond amplifier and other cathodes, will be tested to 0.5 Ampere at the Brookhaven National Laboratory (BNL) in 2007. The status and projected performance for each of these injector projects is presented.

Cyclophosphamide(CY) is an alkylating agent used to treat a variety of autoimmune disorders.Water intoxication is a well-known complication of high-dose intravenous (i.v.) CY, but is rare in patients treated with low dose i.v. CY. We describe two patients with lupus nephritis and water intoxication following low dose i.v. CY. The first patient was treated with oral prednisolone and azathioprine for eight weeks with inadequate response and persistent renal inflammatory activity. Eight hours after the first i.v. CY pulse she had a grand mal seizure. The second patient had WHO class III lupus nephritis, and after a single i.v. CY pulse developed vomiting, diarrhoeaand grand mal seizures.They were both fluid-restrictedand their serum sodium levels returned to normal. In conclusion, even at low doses i.v. CY may induce hyponatremiarelated to inappropriateantidiuretichormone secretion. This potentially life-threateningcomplication of i.v. CY could be minimized by avoidance of overhydrationfollowing pulse i.v. CY.

Jefferson Lab is in the process of building an upgrade to our Free-Electron Laser Facility with broad wavelength range and timing flexibility. The facility will have two cw free-electron lasers, one in the infrared operating from 1 to 14 microns and one in the infrared operating from 0.25 to 1 micron [1]. In addition, there will be beamlines for Thompson-backscattered femtosecond X-rays, and broadband THz radiation. The average power levels for each of these devices will exceed any other available sources by at least 2 orders of magnitude. Timing of the available laser pulses can be continuously mode-locked at least 4 different (MHz) repetition rates or in macropulse mode with pulses of a few microseconds in duration with a repetition rate of many kHz. The status of the construction of this facility and a review of its capabilities will be presented.

In this paper, we study noise-like pulse generation in a km-long fibre ring laser including a double-clad erbium?ytterbium fibre and passively mode-locked through nonlinear polarization evolution. Although single noise-like pulsing is only observed at moderate pump power, pulse energies as high as 120?nJ are reached in this regime. For higher pump power, the pulse splits into several noise-like pulses, which then rearrange into a stable and periodic pulse train. Harmonic mode locking from the 2nd to the 48th orders is readily obtained. At pump powers close to the damage threshold of the setup, much denser noise-like pulse trains are demonstrated, reaching harmonic orders beyond 1200 and repetition frequencies in excess of a quarter of a GHz. The mechanisms leading to noise-like pulse breaking and stable high-order harmonic mode locking are discussed.

In this paper we study a dispersion-managed figure-eight fibre laser generating noise-like pulses with adjustable characteristics. Non-self-starting mode locking leads to the formation of a single noise-like pulse circulating in the cavity. Both the duration of the pulse and its spectral width can be adjusted by tuning the angle of wave retarders, in particular a half-wave retarder that controls the switching power of the polarization-imbalanced nonlinear optical loop mirror that is used as mode locker. Wave retarder tuning also allows observing an abrupt transition between two clearly distinct noise-like pulse regimes, one characterized by a long (>?1?ns) rectangular pulse envelope with a narrow spectrum and the other characterized by shorter sub-ns bell-shaped pulses whose Raman-enhanced spectrum extends far beyond the doped fibre gain spectrum. The existence of two distinct noise-like pulsing modes can be understood in terms of the periodic variation of the pulse spectrum along the cavity, which is able to shift the effective dispersion regime of the laser. By joining the tuning ranges of each regime, the noise-like pulse duration can be adjusted between 57?ps and 6.3?ns, and its bandwidth between 3.5 and 59?nm.

In this work we study multiple noise-like pulse generation in a 320?m long passively mode-locked erbium-doped figure-eight fibre laser in the normal net dispersion regime. The nonlinear optical loop mirror (NOLM) that is used as a mode locker operates through polarization asymmetry, which allows us to control its switching power by birefringence adjustments at the NOLM input, using a half-wave retarder (HWR). Over some range of the HWR orientation, a single noise-like pulse is observed in the cavity. Its peak power is adjustable as it remains clamped to the variable switching power, and its duration varies inversely between ?5 and ?22?ps. Beyond the HWR position, corresponding to the longest duration, the pulse splits into several noise-like pulses. These multiple pulses usually present a walkoff, however they can be synchronized through slight birefringence adjustments, although they are not evenly spaced in time. Up to 12 simultaneous noise-like pulses were observed experimentally, with a duration of ?2?ns. Multiple pulsing and synchronization of the pulses are interpreted in terms of mechanisms of interaction between pulses. Multiple pulsing appears to be indirectly related to the peak power limiting effect of the NOLM.

In this letter, the experimental results on a supercontinuum signal are presented based on a significantly broad and highly flat final spectrum (~810 nm and less than 3 dB). The supercontinuum was induced by two different microstructures in photonic crystal fibers (PCFs) with solid cores, pumped in the nanosecond regime (large pulses) by a Q-switched Nd:YAG laser. The simultaneous presence of both PCFs allowed an optimized spectrum to be obtained in comparison with the work reported in recent papers. The spectral evolution of a pump pulse propagating into the two PCFs was analyzed experimentally and the dispersion in the PCFs was estimated through numerical simulations. The broadening of the final spectrum was related to nonlinear phenomena such as modulation instability, stimulated Raman scattering, four-wave mixing, self-phase modulation, cross-phase modulation and the formation of higher-order solitons. The proposed scheme may have potential applications for the use of supercontinuum spectra in the areas of sensing, spectroscopy and metrology.

In this paper a tunable multi-wavelength erbium doped fiber laser, based on a Mach–Zehnder interferometer, is presented. Here the interferometer is achieved by splicing a piece of photonic crystal fiber (PCF) between two segments of a single-mode fiber. The laser can emit a single, double, triple or quadruple line, which can be tuned from 1530 to 1556 nm by controlling the polarization state. Finally it is shown, by experimental results, that the laser has high stability at room temperature.

We study experimentally a figure-of-eight fibre laser including a polarization-imbalanced nonlinear optical loop mirror and a Mach–Zehnder optical filter formed by two fibre tapers placed in series. Depending on the adjustments of two wave retarders included in the setup, different modes of operation of the laser are found. In continuous-wave mode, tunable single-wavelength operation as well as multiwavelength lasing are observed. For some adjustments, self-pulsing also takes place, although the pulses are very unstable. Finally, for some adjustments a mechanical stimulation (a kick) leads to the onset of passive mode locking. Measurements reveal that the mode-locked pulses actually are noise-like pulses. Both stable fundamental mode locking and second-harmonic mode locking with particular dynamics were obtained. In this work, we analyse how simple wave plate adjustments can lead to such a variety of operational modes of the fibre laser.

This is a retrospective study of 19 cases of subtalar dislocation treated in our Department during the last 15 years. The average age of the patients was 31, and the majority were male (63%). Medial dislocations predominated (84%) and 37% were open. Associated osteocartilaginous lesions were very frequent and affected 13 patients (68%). Surgery was required for all the open injuries and for 2 of the closed dislocations. Closed reduction was impossible in one, and another required surgery to treat an associated vascular injury. Seventeen of the 19 patients were reviewed after an average of 7.9 years. The results were good in 6, fair in another 6, and poor in the remaining 5. The results of all the open lesions was only fair or poor. Four patients needed a triple arthrodesis. Factors resulting in a poor result were open lesions, associated bone lesions, and prolonged immobilization.

We propose and study experimentally and numerically a passively mode-locked figure-eight fiber laser scheme generating noiselike optical pulses, or subns wave packets with a fine inner structure of subps pulses presenting random amplitudes and durations. The particular design of the nonlinear optical loop mirror (NOLM) used in this laser, relying on nonlinear polarization rotation, allows adjusting the switching power through input polarization control. Experimental results show stable pulsed operation over a limited range of the NOLM input polarization angle. Interestingly, the spectral and temporal characteristics of these pulses are observed to be widely variable over that range. In particular, the spectral width varies from 16 to 52 nm and this spectral variation is associated with an inverse evolution in the durations of the bunch and of the inner ultrashort pulses. Simulation results are in good agreement with the experiment. They confirm the strong dependence of the pulse properties on the value of the NOLM switching power, although NOLM switching is not alone responsible for the appearance of the noiselike pulsing mode.

In this work we prepared a series of GaZn/TiO2 (5 wt%, 10 wt%, and 15 wt% of Ga) photocatalysts by the sol-gel method. The X-ray diffraction results showed the presence of TiO2 in anatase phase. Also, in the GaZn/TiO2 system a small peak assigned to Ga2O3 is present. The specific surface area of the Zn/TiO2 is 97 m2/g and the specific surface area increases to 132 m2/g when the amount of Ga increases. The energy band gap values obtained by UV-VIS diffuse reflectance spectroscopy are 2.9, 3.12 and 3.15 eV for 5GaZn/TiO2, 10GaZn/TiO2 and 15GaZn/TiO2 respectively. The results of the photocatalytic activity show that the total destruction of phenol is more efficient in GaZn/TiO2 than in the Zn/TiO2 photocatalysts.

We demonstrated that the bandwidth control in supercontinuum source is possible through polarization effects induced on a PCF. The spectral width obtained can be selected from 740 nm-1430 nm while it maintains a good flatness.

Peroxides are compounds related to rancidity in oils. A peroxides index sensing setup based on a Mach-Zehnder interferometer is presented. The output power spectrum shift occurs from 1490 to1580 [nm] with sensitivity of 0.88 [nm/meq/kg].