An all-optical tunable wavelength converter using a combination of self-phase modulation (SPM) effects in highly nonlinear microstructure fibers and narrowband spectral filtering is investigated, which is reported for the first time to our knowledge. Wavelength conversion over a±4nm bandwidth of a 10Gb/s date rate is obtained with good efficiency. A 25-m-long microstructure fiber with zero-dispersion wavelength at 800nm is used as the nonlinear medium. The core diameter of microstructure fiber is 2.4μm and the outer diameter is 125μm. The nonlinearity is γ=36km-1W-1, which is 20 times higher that that of a conversional dispersion-shifted fiber. The dispersion at the wavelength of 1550nm is ~+150ps/nm-km and the loss is 40dB/km.
In this paper, the experiment on all-optical switching based on microstructured optical fiber (MOF) is reported. In experiment, a 25-meter-long MOF(γ=36W-1km-1@1550nm) is used as nonlinear medium of nonlinear optical loop mirror and the input signal is generated by a 10GHz tunable picosecond laser source (u2t TMLL1550), with a full-width at half-maximum (FWHM) pulse width of 2 ps centered at 1550 nm. With the increase of input power, a π nonlinear phase shift is obtained by 40/60 coupler in experiment, but the same thing not be found by 48/52 coupler. Strong confinement of electromagnetic radiation in the fiber core allow that microstructured optical fiber can have a much higher nonlinearity per unit length than conventional fibers, and consequently devices based on such fibers can be much shorter in length than their conventional counterparts. Additionally, the switching can also be used as reshaping devices.
In this paper, a novel structure design of all-fiber tunable compressor has been proposed which based on two cascaded uniform fiber Bragg gratings and a Piezoelectric Ceramic is used to make the compressor posses tunable function. By simulating numerically the evolution of picosecond pulses in the compressor, we have found that picosecond pulses can be compressed effectively, if the parameters of gratings and pulses were chosen properly. Additionally, the further study reveals that the width of output pulse could become narrower and the fiber gratings needed would be shorter, if the negative chirp of initial pulse were induced by pulse laser.
A novel technique is proposed for pulse compression by utilizing the nonlinear interaction between two neighboring pulses in optical fiber. By using the method of split-step Fourier (SSF), we numerically investigate the propagation of the pulse pair in optical fiber. Usually, two pulses attract each other and collide into one compression pulse periodically along the fiber. So with an appropriate choice of the fiber length-the collision length, such a fiber can act as compressor, so-called nonlinear action compressor. And then, the effects of parameters on the compression pulse have
also been investigated numerically with SSF and we find the quality factor Qc>1.