摘要:
An optical device comprises a substrate having at least one light-guiding core and cladding material surrounding the core; a cladding-modifying element disposed alongside, at least in part, a portion of the light-guiding core, the cladding-modifying element being formed of a material different to the cladding material so that the refractive index difference between the material of the cladding-modifying element and the cladding material is dependent upon the temperature of the cladding-modifying element; and a heating and/or cooling arrangement for altering the temperature of the cladding-modifying element.
摘要:
An optical waveguide grating if formed in a waveguide of nominally uniform diameter. A grating characteristic is varied at positions along the grating in a substantially inverse relationship to the diameter of the waveguide at those positions.
摘要:
An optical fiber transmission system comprises an optical signal source operable to generate an optical signal at a predetermined bit rate and at a signal wavelength; an optical fiber transmission link connected at a first end to the signal source, the link having dispersion characteristics at the signal wavelength; an optical amplifier serially disposed in the link; and a signal receiver connected at the second end of the Lank; in which a grating is connected in the link, the grating being chirped by an amount providing at least partial compensation of the dispersion characteristics of the link, the compensation such as to provide a signal, at the second of the link, compatible with the sensitivity requirements of the receiver at the second end of the link.
摘要:
The invention provides a method of manufacturing a chirped optical fiber grating, the method comprising the steps of an etching the cladding of the optical fiber to vary the cross-sectional area of a portion of an optical fiber, and impressing a grating of uniform pitch on the portion of the fiber in which the portion of the fiber is subjected to different respective longitudinal forces during the impressing step and during subsequent use of the grating.
摘要:
The present invention provides a MEMS package, the MEMS package comprising a substrate which comprises a recess, and a MEMS device, situated in the recess.
摘要:
An arrayed waveguide grating (AWG) device (1) comprising a substrate having a first array of waveguides (8) optically coupled between first and second slab couplers (3, 4) and a second array of input-output waveguides (10) optically coupled at first ends thereof to an input/output side (5) of the second slab-coupler (4). The input/output waveguide are tapered at first end portions (13) thereof so as to increase in width towards the second slap coupler, and the width (W) of the first ends of the input/output waveguides varies across the second array (10) in a manner so as to increase uniformity of at least on performance parameter, for example adjacent crosstalk (AXT). In the described embodiment, the width (W) of the tapered waveguide ends increases from one side to the array of input/output waveguides (10) to the other, so as to keep the separation (s) between the input/output waveguides.
摘要:
An optical waveguide (1) with a multi-layer core (6) comprises a substrate (2), a composite core waveguide (7) formed on the substrate (2) and at least one upper cladding layer (8) embedding said core waveguide (7). The core waveguide (7) is characterized by a composite core layer (6) comprising a first core layer (4) with a consolidation temperature T1C formed on the substrate (2) and at least one other core layer (5) formed on the first core layer (4), wherein the softening temperature T2S of at is least one of said at least one other core layers (5) is equal to or less than the consolidation temperature T1C of at least one underlying core layer (4, 5).
摘要:
An optical fiber transmission system includes an optical transmitter for generating light; a dispersive optical fiber link optically coupled to the optical transmitter, for transmitting the light generated by the optical transmitter; and a chirped optical fiber grating, optically coupled to the optical transmitter and to the dispersive optical fiber link, for providing at least a partial dispersion compensation to the light generated by the optical transmitter, before the light is transmitted in the dispersive optical fiber link; the chirped optical fiber grating including a polarization-maintaining optical fiber having a chirped refractive index variation
摘要:
An optical grating fabrication apparatus having a phase mask for dividing an incident light beam into a plurality of diffracted beams and a focusing arrangement for receiving light from the phase mask and converging at least two non-zero-order diffracted beams together so as to generate an interference region of a characteristic period between the converged beams so that a grating structure can be impressed on an optical waveguide placed in the interference region. Further, a translation stage is arranged to move the phase mask and at least a part of the focusing arrangement with respect to one another under control of a control circuit so as to alter the angle of convergence of the converged beams and thus controllably tune the characteristic period.
摘要:
An optical fiber, a section of length (Lgr) which is modulated in refractive index so as to form a grating with a plurality of characteristics reflection wavelength channels, has a refractive index modulation comprising an amplitude modulation having an underlaying higher frequency component defining the shape of the reflection profile of each of the wavelength channels and, superposed thereon, a lower frequency component of period P imposing repeated envelopes over the higher frequency component and defining the separation of the wavelength channels. In one embodiment, the lower frequency component has the shape of a sinc-function with varying refractive index (&dgr;n) and with discrete &pgr;-phase shifts (&dgr;&phgr;) each envelope, to form a sinc-sampled grating. Chirped multi-channel optical fiber gratings may thus be provided for dispersion compensation in long-haul transmission links.