摘要:
A wavelength converter using difference frequency generation (DFG) is disclosed. In one embodiment, the wavelength converter comprises (a) a first optical filter configured to filter out one or more lightwaves requiring wavelength conversion from wavelength-division multiplexed (WDM) lightwaves, and (b) a broadband multi-channel simultaneous wavelength conversion portion comprising a pump source that generates pump light for use in the process of the DFG, a first optical combiner for combining said pump light with said filtered lightwaves, a high non-linear medium configured to generate wavelength converted lightwaves from said filtered lightwaves using the DFG, and a second optical filter for filtering said wavelength converted from said filtered lightwaves.
摘要:
Solely lightwaves required to be wavelength converted are filtered out from the input broadband WDM lightwaves and are wavelength converted by use of FWM. Not only the broadband simultaneous wavelength conversion that is studied by many researchers, but also more flexible, sub-band wavelength conversion is realized. Frequency interval of the input WDM lightwaves is broadened or reduced in comparison of the frequency interval of the WDM lightwaves inputted to the wavelength converter. The frequency interval variation techniques using the wavelength converter, it can be realized to transfer from a transmission line less influenced by inter-channel crosstalk due to FWM to the different transmission lines strongly influenced by inter-channel crosstalk due to FWM, and vice versa.
摘要:
The present invention provides a pulse train generator comprising: a dual-frequency signal light source for generating a dual-frequency signal; a soliton shaper for soliton-shaping output light from the dual-frequency signal light source; and an adiabatic soliton compressor for performing adiabatic soliton compression on output light from the soliton shaper, and also provides a waveform shaper used in this pulse train generator, including a plurality of highly nonlinear optical transmission lines and a plurality of low-nonlinearity optical transmission lines which has a nonlinearity coefficient lower than that of the plurality of highly nonlinear optical transmission lines and which has a second-order dispersion value of which an absolute value is different from that of the plurality of highly nonlinear optical transmission lines. Further, the present invention provides a light source comprising a plurality of continuous light sources of which at least one oscillates in a multimode; a multiplexer for multiplexing output light from the continuous light sources; and a nonlinear phenomenon producer for producing a nonlinear phenomenon on output light from the multiplexer so as to suppress SBS (Stimulated Brillouin Scattering).
摘要:
The present invention provides a pulse train generator comprising: a dual-frequency signal light source for generating a dual-frequency signal; a soliton shaper for soliton-shaping output light from the dual-frequency signal light source; and an adiabatic soliton compressor for performing adiabatic soliton compression on output light from the soliton shaper, and also provides a waveform shaper used in this pulse train generator, including a plurality of highly nonlinear optical transmission lines and a plurality of low-nonlinearity optical transmission lines which has a nonlinearity coefficient lower than that of the plurality of highly nonlinear optical transmission lines and which has a second-order dispersion value of which an absolute value is different from that of the plurality of highly nonlinear optical transmission lines. Further, the present invention provides a light source comprising a plurality of continuous light sources of which at least one oscillates in a multimode; a multiplexer for multiplexing output light from the continuous light sources; and a nonlinear phenomenon producer for producing a nonlinear phenomenon on output light from the multiplexer so as to suppress SBS (Stimulated Brillouin Scattering).
摘要:
The present invention provides a method for generating four-wave mixing to obtain idler light with high efficiency, in which the range of lengths of an optical fiber is appropriately set, and probe light and pumping light, having different frequencies, are launched into the optical fiber. When the nonlinear coefficient of the optical fiber, the loss per unit distance, and the wavelength and intensity of the probe light and pumping light are set to certain values, the idler light conversion efficiency at the output end of the optical fiber is a periodic function with respect to optical fiber length having a maximal value and a minimal value. The maximum length of the optical fiber to be used to obtain four-wave mixing is set to be equal to or less than the length Lmax (Lmax=Lm+&Dgr;L) which is given by adding the length of the optical fiber Lm, at which the idler light conversion efficiency takes on the first maximal value in the aforementioned periodic function and distance &Dgr;L or 10% of Lm.
摘要:
In an optical gain equalizer according to the present invention, a plurality of etalon filters 1 and one ore more fiber gratings 2 or dielectric multilayer filters 3 are arranged in line, and a beam of light externally applied is passed through the etalon filters 1 and the fiber gratings 2 or dielectric multilayer filters 3 and outputted to the outside, and the etalon filters 1 have sinusoidal wave loss characteristic of the same amplitude and period as those of the term obtained by Fourier series expansion of the loss wavelength characteristic for gain flattening, and the one or more fiber gratings 2 or dielectric multilayer filters 3 compensate the ripple component remaining as the difference between the loss wavelength characteristic for gain flattening and the loss wavelength characteristic owing to the etalon filters 1. An optical amplifying device 14 is constituted by combining an optical amplifier 5 with the optical gain equalizer 4. A wavelength-division multiplex transmitter is constituted by using the optical amplifying device 14.
摘要:
The present invention provides a pulse train generator comprising: a dual-frequency signal light source for generating a dual-frequency signal; a soliton shaper for soliton-shaping output light from the dual-frequency signal light source; and an adiabatic soliton compressor for performing adiabatic soliton compression on output light from the soliton shaper, and also provides a waveform shaper used in this pulse train generator, including a plurality of highly nonlinear optical transmission lines and a plurality of low-nonlinearity optical transmission lines which has a nonlinearity coefficient lower than that of the plurality of highly nonlinear optical transmission lines and which has a second-order dispersion value of which an absolute value is different from that of the plurality of highly nonlinear optical transmission lines. Further, the present invention provides a light source comprising a plurality of continuous light sources of which at least one oscillates in a multimode; a multiplexer for multiplexing output light from the continuous light sources; and a nonlinear phenomenon producer for producing a nonlinear phenomenon on output light from the multiplexer so as to suppress SBS (Stimulated Brillouin Scattering).
摘要:
An optical pulse generator comprises a comb-like dispersion profiled fiber formed into an optical loop mirror. The fiber may comprise three or more segments of fiber having alternating highly dispersive and highly nonlinear characteristics. The optical loop mirror construction splits an input pulse into two portions that propagate through the CDPF in opposite directions. The pulse portions are re-combined, and a compressed pulse with reduced noise is produced.
摘要:
A wavelength of pump is set to an anomalous dispersion area of an optical fiber for wavelength conversion and pump power is set to be larger than a predetermined threshold of MI so that wavelength conversion capable of flattening conversion efficiency spectrum within a wide bandwidth is permitted. A pumping source can oscillate a lightwave having a wavelength in the anomalous dispersion region of the optical fiber for wavelength conversion and intensity which can flatten the conversion efficiency spectrum over the wide bandwidth. By causing the DFWM by setting the wavelength of the pump to a wavelength &lgr;p with respect to an optical signal having a center wavelength &lgr;s, the optical signal is converted to a wavelength &lgr;c=(&lgr;s·&lgr;p)/(2&lgr;s−&lgr;p), and by previously seeking the wavelength &lgr;s of the optical signal before conversion and the wavelength &lgr;c of the optical signal after conversion, the wavelength of the pump is set to the wavelength &lgr;p=2(&lgr;s·&lgr;c)/(&lgr;s+&lgr;c), and the wavelength of the pump can flatten the conversion efficiency.
摘要:
The present invention provides a pulse train generator comprising: a dual-frequency signal light source for generating a dual-frequency signal; a soliton shaper for soliton-shaping output light from the dual-frequency signal light source; and an adiabatic soliton compressor for performing adiabatic soliton compression on output light from the soliton shaper, and also provides a waveform shaper used in this pulse train generator, including a plurality of highly nonlinear optical transmission lines and a plurality of low-nonlinearity optical transmission lines which has a nonlinearity coefficient lower than that of the plurality of highly nonlinear optical transmission lines and which has a second-order dispersion value of which an absolute value is different from that of the plurality of highly nonlinear optical transmission lines. Further, the present invention provides a light source comprising a plurality of continuous light sources of which at least one oscillates in a multimode; a multiplexer for multiplexing output light from the continuous light sources; and a nonlinear phenomenon producer for producing a nonlinear phenomenon on output light from the multiplexer so as to suppress SBS (Stimulated Brillouin Scattering).