摘要:
A chromatic dispersion compensator of the present invention includes an optical circulator or a directional coupler having a first, second and third ports; an input transmission path connected to the first port; an output transmission path connected to the third port; a chirped grating connected to the second port; and a dispersion compensating fiber connected to at least one of the first, second and third ports, the dispersion compensating fiber and the chirped grating giving chromatic dispersion characteristic reverse to the chromatic dispersion characteristic of the input and output transmission path. In the wavelength compensator, the optical signal is incident into the first port from the input transmission path, and is made to go out to the chirped grating from the second port. Further, the optical signal is incident from the chirped grating to return to the second port, and is made to go to the output transmission path from the third port.
摘要:
Un filtre passe-bande, inscrit dans un guide d'onde optique, comporte au moins un réseau de Bragg (BG1) créant un couplage entre deux modes de propagation. Selon un mode de réalisation, le pas (s) du réseau est égal à la longueur de battement de ces deux modes, pour créer un couplage co-directionnel pour les modes LP01 et LP0i. Selon un autre mode de réalisation, le réseau couple le mode LP01 à un mode de radiation contradirectionnel quelconque. Il comporte, au moins en un point de ce réseau, une zone (PS1) où une demi-période du réseau est omise pour créer un déphasage de π entre les deux modes couplés.
摘要:
The emission waveband of a data modulated (22) laser (20) signal is locked to the reflection waveband of a chirped Bragg grating dispersion compensator (10, 11, 12) by means of a phase locked loop regulating the temperature of the laser or the magnitude of the drive current applied to it.
摘要:
A chromatic dispersion compensator of the present invention includes an optical circulator or a directional coupler having a first, second and third ports; an input transmission path connected to the first port; an output transmission path connected to the third port; a chirped grating connected to the second port; and a dispersion compensating fiber connected to at least one of the first, second and third ports, the dispersion compensating fiber and the chirped grating giving chromatic dispersion characteristic reverse to the chromatic dispersion characteristic of the input and output transmission path. In the wavelength compensator, the optical signal is incident into the first port from the input transmission path, and is made to go out to the chirped grating from the second port. Further, the optical signal is incident from the chirped grating to return to the second port, and is made to go to the output transmission path from the third port.
摘要:
Broadband in-line gratings (19, 30) in optical waveguides (17) are disclosed. The gratings have a bandwidth of at least 2 nm (preferably at least 4 nm) and a peak reflectivity of at least 70% (preferably at least 90%). Exemplarily, such gratings can be formed in H₂-treated Si-based fibers that support a normalized index change of at least 10⁻³. Gratings according to the invention can be used, for instance, to form pump radiation reflectors in an optical fiber communication system (10) with Er-doped fiber amplifiers, or to flatten the amplifier gain curve. The gratings can be of the blazed or non-blazed type.
摘要:
An optical waveguide light redirecting arrangement includes an optical waveguide having at least two solid portions each of which guides light in a path along a longitudinal axis, with at least one grating region being embedded in each solid portion. Each grating region includes a multitude of grating elements extending at such identical longitudinal spacings and at such an identical angle relative to the longitudinal axis as to redirect light reaching the grating elements between the path of one and the path of the other of the waveguiding portions.
摘要:
A wavelength-selective add-drop multiplexer is disclosed for adding and/or dropping spectral components from a wavelength-division-multiplexed optical signal. (1x1) or (2x2) optical switches are used, either alone or in conjunction with other optical elements, to separate spectral components identified for drop from other spectral components.
摘要:
There is disclosed an optical device for dispersion compensation of channels within a predetermined wavelength band, comprising: a waveguiding structure; and a grating structure formed in said waveguiding structure; characterized in that said grating structure has a Bragg frequency profile that is divided into contiguous periods, wherein the Bragg frequencies within each period vary between a lower Bragg frequency and an upper Bragg frequency, said lower and upper Bragg frequencies for each period both corresponding to wavelengths outside of said predetermined wavelength band.
摘要:
A wavelength-selective add-drop multiplexer is disclosed for adding and/or dropping spectral components from a wavelength-division-multiplexed optical signal. (1×1) or (2x2) optical switches are used, either alone or in conjunction with other optical elements, to separate spectral components identified for drop from other spectral components.