摘要:
A method of manufacturing a fiber-optical coupling element by fusion of two monomode fibers. The fiber cores are made of a core glass, the American softening temperature of which is at least 80.degree. C. higher than that of the cladding glass. The fibers are heated to a temperature between 520.degree. and 560.degree. C. By the method, fibers can be fused to form a coupling element without undesirable deformation of the fiber cores.
摘要:
The invention relates to an optical demultiplexer whose "color band" is adjustable, so that the demultiplexer can always be adapted to future standards. The adjustment is performed either by tilting the optical grating with respect to the light beam incident thereon or by deflecting the light by means of a liquid crystal arranged in the light path.
摘要:
A method of manufacturing a geodetic-optical component is described in which non-spherical rotationally symmetrical recesses are formed in a surface of a substrate, and the surface with the recesses are covered with a planar waveguide. This technique forms the recesses in a laminated substrate having a number of layers of varying etching rates, and then etching these layers to form cup-shaped recesses.
摘要:
The invention relates to a method of and a device for providing an outer surface of an envelope which is concentric to a light-conductive core, around a monomode optical fiber. According to the invention, the eccentricity of the fiber and the envelope may be for example, 0.1 .mu.m for a core diameter of 3 .mu.m. This accuracy is acieved by splitting a light beam, emerging from the end of a fiber which is clamped in an envelope, into two subbeams by means of rotating optical means, each of the beams producing a circular image. By a suitable choice and adjustment of the optical means, the two light beams will form oppositely moving images when the fiber end is displaced with respect to the axis of rotation and observation. When the images are concentric, the fiber end is situated on the axis of rotation. Machining of the envelope by the use of a tool which rotates around the axis of rotation results in an envelope which is concentric to the light-conductive core of the fiber.
摘要:
The invention relates to a method of manufacturing an optical grating from a body having a surface which is provided with equidistant grooves. In order to obtain cheap and deformation-resistant gratings, according to the invention a surface of a substrate is provided with a number of layers of substantially equal thicknesses. The etching rates of the layers (in a given etchant) increase substantially proportionally to the number of the layer. A cross-sectional surface of the layers is then exposed to the etchant to form the surface with the grooves.
摘要:
A coupling element for coupling a laser radiation source to a monomode optical transmission fiber. The end of the fiber is monotonically flattened at a temperature at which the fiber core has a viscosity of between 10.sup.7 to 10.sup.8.5 poises. The fiber has a cladding glass chosen to have a viscosity of between 10.sup.10 -10.sup.11 poises at the flattening temperature. This causes the core glass to emerge in the form of a semi-ellipsoidal lens, when the fiber is flattened.
摘要:
Method of producing a coupling element for coupling a laser radiation source to a monomode optical transmission fiber. The end of the fiber is monotonically flattened at a temperature at which the fiber's core has a viscosity of between 10.sup.7 to 10.sup.8.5 poises. The fiber has a cladding glass chosen to have a viscosity of between 10.sup.10 -10.sup.11 poises at the flattening temperature. This causes the core glass to emerge in the form of a semi-ellipsoidal lens, when the fiber is flattened.
摘要:
In an optical soliton transmission system an optical transmitter (2) generating short pulses is coupled to a glass fiber cable (4) comprising sections of glass fiber (7, 9, 11, 13, 15) with interspaced semiconductor laser amplifiers (8, 10, 12, 14). An optical receiver (6) is connected to the end of the glass fiber cable (15). In optical soliton transmission Erbium doped fiber amplifiers and dispersion shifted fiber are currently used in the 1.5 .mu.m wavelength region. However, by utilizing standard fiber in the 1.3 .mu.m wavelength region it is possible to use a lower soliton power compared with a state-of the-art transmission system.
摘要:
In an optical heterodyne or homodyne receiver an optical system (140) is used in which the local oscillator beam (L) is combined with the signal beam (S). Simultaneously, these beams are split into orthogonally polarized sub-beams. For this purpose the optical system (140) comprises polarization-sensitive beam-splitting layers (141a and 141b) and neutral beam-splitting layers (142a and 142b) which function as beam-combining elements. In order to align the directions of the exit sub-beams of the signal beam (.sub.11, S.sub.12, S.sub.2, S.sub.22) and the local oscillator beam (L.sub.11, L.sub.12, L.sub.21, L.sub.22), the angles (.alpha., .beta., .gamma., .delta.) enclosed by the beam-splitting faces are chosen to be such that two angles located opposite each other have a combined magnitude of 180.degree.. This is realised by providing the layers (141a, 142b and 141b, 142a) on side faces of one prism (140a, 140b).
摘要:
A monomode optical transmission fibre (1) is described, having a tapered end portion (5) on which a lens (10) is arranged. This lens is obtained by immersing the fibre end in a transparent liquid material (7) whose melting temperature is lower than that of the fibre materials and whose refractive index is substantially equal to that of the fibre core (2), and by allowing the drop which adheres to the fibre after withdrawal to solidify.