Abstract:
A broadband light source that outputs broadband light with reduced peak power includes a pulsed light source, an optical fiber, a band-elimination filter, and a light echo unit. The optical fiber receives pulsed light output from the pulsed light source, expands the spectrum of the pulsed light by a nonlinear optical effect within the fiber to generate supercontinuum light, and outputs the supercontinuum light. The light echo unit has a plurality of optical paths between an input terminal and an output terminal thereof. At least one optical path in the plurality of optical paths serves as a loop optical path. The light echo unit receives, via the input terminal, the supercontinuum light output from the optical fiber and having traveled through the band-elimination filter, guides the supercontinuum light through the plurality of optical paths, and outputs the supercontinuum light guided by the plurality of optical paths from the output terminal.
Abstract:
A broadband light source unit that produces a supercontinuum lightwave having a flat spectral form and has a light source that outputs a first source lightwave, which is a pulse lightwave having periodic pulses with a constant intensity, an intensity modulator that receives the first source lightwave, produces a second source lightwave having pulses whose intensities are different from one another, and outputs it, and a nonlinear optical medium section that receives the second source lightwave, produces a supercontinuum lightwave having a wavelength band broadened through a nonlinear optical phenomenon, and outputs it. An optical analyzer includes a light-applying section that applies a supercontinuum lightwave outputted from the broadband light source unit to a light-receiving region of a measurement-undergoing object, and an image pickup section that receives a lightwave generated at the light-receiving region by the application of the supercontinuum lightwave and picks up an image of the measurement-undergoing object.
Abstract:
The invention offers a broadband light source unit that produces using a simple system a supercontinuum lightwave having a flat spectral form and an optical analyzer using the unit. The broadband light source unit has a light source that outputs a first source lightwave, which is a pulse lightwave having periodic pulses with a constant intensity, a conversion means that receives the first source lightwave, produces a second source lightwave having pulses whose intensities are different from one another, and outputs it, and a nonlinear optical medium section that receives the second source lightwave, produces a supercontinuum lightwave having a wavelength band broadened through a nonlinear optical phenomenon, and outputs it. The optical analyzer has the foregoing broadband light source unit, a light-applying section that applies a supercontinuum lightwave outputted from the broadband light source unit to a light-receiving region of a measurement-undergoing object, and an image pickup section that receives a lightwave generated at the light-receiving region by the application of the supercontinuum lightwave and picks up an image of the measurement-undergoing object.
Abstract:
An apparatus and method are provided for filtering an optical signal by wavelength. An initially polarised signal is passed through a DGD element effective to alter the polarisation state of the components of the signal according to wavelength. A polarisation filter (polariser) is then provided to attenuate light having given polarisation states from the signal, thereby attenuating the wavelengths associated with said polarisation states. The invention finds particularly utility in the domain of vestigial sideband filtering, allowing the bandwidth of signals within a wavelength division multiplexed system to be reduced without introducing the deleterious effects associated with conventional wavelength filters.
Abstract:
A programmable, ultrafast optical delay line based on reversible frequency conversion uses a time-prism pair and no moving parts. A first electro-optic phase modulator acting as a first time-prism shifts the frequency of an incoming pulse train. The pulse train passes through a dispersion element, such as a dispersive fiber, which delays the pulse train by an amount that is directly proportional to the magnitude of the frequency shift, which in turn is proportional to the magnitude of the phase modulator drive voltage. A second electro-optic phase modulator is driven π out of phase to the first modulator and restores the frequency of the delayed pulse train to the original frequency of the incoming pulse train. To reduce pulse broadening effects and enhance performance further, soliton propagation inducing elements can be employed between the time-prisms.
Abstract:
Le domaine général de l'invention est celui des dispositifs de génération photonique de signaux microondes arbitraires modulés linéairement en fréquence comprenant un laser (1), un ensemble (2) de mise en forme du signal émis et un photorécepteur (3) dont la bande passante est dans le domaine des fréquences microondes. L'ensemble de mise en forme comporte: − Un premier séparateur optique (20); − Une première voie optique comportant une boucle à décalage de fréquence comprenant un séparateur optique (50), un premier amplificateur optique (60), un isolateur optique (70), un premier filtre optique spectral (75) et un décaleur (80) acousto-optique de fréquences; − Une seconde voie optique comportant un décaleur (30) électro-optique de fréquences; − Un second séparateur optique (40); − Un second amplificateur optique (90); − Un second filtre optique (100); la fréquence de décalage acousto-optique, la fréquence de décalage électro-optique et le gain d'amplification du premier amplificateur optique étant réglables.
Abstract:
PROBLEM TO BE SOLVED: To provide a wide-band light source capable of outputting wide-band light with a reduced peak power.SOLUTION: A wide-band light source 1 includes a pulse light source 10, an optical fiber (nonlinear optical medium) 11, a band attenuation filter 12, and an optical echo part 20. The optical fiber 11 receives pulse light outputted from the pulse light source 10 and spreads a spectrum of the pulse light by nonlinear optical effects thereinside to generate super-continuum light and outputs the super-continuum light. The optical echo part 20 has a plurality of optical paths between an input end and an output end, and at least a part of some of the plurality of optical paths is formed into a circulating optical path. The super-continuum light which has been outputted from the optical fiber 11 and has passed the band attenuation filter 13 is inputted to the input end of the optical echo part 20 and is guided along the plurality of optical paths, and the super-continuum light guided along the plurality of optical paths is outputted from the output end.
Abstract:
PROBLEM TO BE SOLVED: To write or read out a light pulse as a signal light into/from an optical storage element in every pulse. SOLUTION: This optical buffer device 10 is provided with the plurality of optical storage elements 20 capable of holding a light, and optical delay elements 30. The plurality of optical storage elements is arranged arrayedly on an optical path with a signal light and a control light propagated therethrough reverse-directionally each other. Each optical delay element is provided between the adjacent optical storage elements. The respective optical delay elements impart different delays to the signal light and the control light. Each optical storage element is provided with an optical waveguide propagating the signal light and the control light, and an optical resonator provided adjacently to the optical waveguide, in a favorable embodiment of the optical buffer, and coupling between the optical waveguide and the optical resonator is generated or released in response to the presence of an input of the control light. COPYRIGHT: (C)2009,JPO&INPIT
Abstract:
An apparatus and method are provided for filtering an optical signal by wavelength. An initially polarised signal is passed through a DGD element effective to alter the polarisation state of the components of the signal according to wavelength. A polarisation filter (polariser) is then provided to attenuate light having given polarisation states from the signal, thereby attenuating the wavelengths associated with said polarisation states. The invention finds particularly utility in the domain of vestigial sideband filtering, allowing the bandwidth of signals within a wavelength division multiplexed system to be reduced without introducing the deleterious effects associated with conventional wavelength filters.