40results about How to "Reduced polarization dependence" patented technology

An optical device 1 has a substrate 2, whereas bare fibers 5 exposed from a coated optical fiber tape 3 by removing a coating 4 from its middle part are secured to the upper face part of the substrate 2. In the substrate 2, a transverse groove 8 is formed obliquely with respect to an axis of the bare fibers 5 so as to traverse core parts 5a of the bare fibers. An optical member 9 for reflecting a part of signal light transmitted through the bare fibers 5 is inserted in the transverse groove 8. A support member 10 is provided on the upper side of the bare fibers 5, whereas a support surface 10a of the support member 10 is provided with photodetectors 11 for detecting light reflected by the optical member 9. The support surface 10a of the support member 10 is inclined with respect to the upper face of the substrate 2, whereby the light entrance surface 13 of each photodetector 11 is inclined by a predetermined angle with respect to the upper face of the substrate 2. Such a configuration realizes an optical device which can lower the polarization dependence of received light in the photodetectors.

In an optical interferometer, polarization dependence attributable to the optical path difference has conventionally been eliminated by inserting a half-wave plate at the center of the interferometer. However, light induced by polarization coupling produced in directional couplers used in the optical interferometer causes interference having different interference conditions from those of the normal light. Polarization rotators that effect any one of 90° rotation and −90° rotation of all states of polarization of incoming light are inserted in the optical interferometer, and thereby the interference conditions of light induced by polarization coupling are made the same as those of the normal light. Each of the polarization rotators is implemented by using two half-wave plates and by varying an angle of combination of these half-wave plates. Alternatively, each of the polarization rotators is implemented through a combination of one half-wave plate and a waveguide having birefringence properties.

There is provided a planar optical waveguide element in which an optical waveguide comprises a core, and a gap portion that is positioned in a center of a width direction of the core so as to extend in a propagation direction of guided light, and that has a lower refractive index than that of the core; and wherein the core comprises two areas that are separated by the gap portion, and a single mode optical waveguide, in which a single mode is propagated span crossing these two areas, is formed.

A tunable filter includes a polarizing beam splitter and a half-wave plate that produce two equally polarized beams from an arbitrarily polarized input light. The polarized beams are directed toward a tunable component that consists of an optical substrate coated with a filter and a reflective element on its back and front surface, respectively. The pass and stop beams emerging from the tunable component are retro-reflected by roof structures and passed again through the filter. As a result of this combination of components, the filter's performance is not dependent on polarization and the filter's output channels are not shifted or deviated by tuning.

In a diffraction grating element 10, between a first medium 11 and a fourth medium 14, a second medium 12 and a third medium 13 are disposed alternately to form a diffraction grating. The light, which enters the diffraction grating from the first medium 11, is diffracted at the diffraction grating portion and output to a fourth medium 14. Or, the light, which enters the diffraction grating from the fourth medium 14, is diffracted at the diffraction grating portion and output to the first medium 11. The index of refraction n₁-n₄ of each medium satisfies a relational expression of “n₃<n₁<n₂, n₃≦n₄≧n₂” or “n₃≦n₁≦n₂, n₃<n₄<n₂”.

Apparatus for a spatially resolved temperature measurement, with at least one optical fiber (6) for the spatially resolved temperature measurement, and at least one laser light source (2) producing light (3, 23) which can be coupled into the optical fiber (6), wherein the portions of the light (3, 23) backscattered in the optical fiber (6) can be coupled out of the optical fiber (6) and evaluated. The apparatus further includes means for reducing polarization-induced effects, wherein the means may be, for example, a polarization modifier (4) capable of at least partially depolarizing the light (3).

Provided is a polymeric optical device comprising a substrate, a lower cladding layer formed on the substrate, at least one core layer pattern formed on a predetermined region of the lower cladding layer and an upper cladding layer having at least two sub-upper cladding layers and formed on the lower cladding layer in which the core layer pattern is formed, and a method of fabricating the same, whereby birefringence of a polymeric optical device could be improved and polarization dependence could be reduced by adjusting the thickness of the sub-upper cladding layer and the number of stacks thereof.

The invention provides a superconducting nanowire single photo detector for suppressing polarization sensitivity. The superconducting nanowire single photo detector comprises a substrate, a high-reflective film, a superconducting nanowire and a medium layer, wherein the high-reflective film is arranged on a surface of the substrate, the superconducting nanowire is arranged on a surface of the high-reflective film, and the medium layer is arranged on the surface of the high-reflective film and wraps the superconducting nanowire. In the superconducting nanowire single photo detector for suppressing the polarization sensitivity, the superconducting nanowire is processed and prepared on the high-reflective film, light can directly irradiate the superconducting nanowire through front-surface optical coupling according to a device structure, the problem of remote focusing in an optical cavity structure can be avoided, the influence of a substrate Fabry-Perot cavity on absorption efficiency is further prevented, the superconducting nanowire single photo detector has relatively high absorption efficiency on a target wavelength, and the detection efficiency of the device is effectively improved; and meanwhile, in the superconducting nanowire single photo detector for suppressing the polarization sensitivity, the polarization correlation of the device can be reduced by growing the high-reflectivity medium layer which wraps the superconducting nanowire on the surface of the high-reflective film.

A photosensitive composition for optical waveguides comprising of an organic oligomer, a polymerization initiator and a crosslinking agent, the organic oligomer being a silicone oligomer represented by the following formula (1), wherein X denotes hydrogen, deuterium, halogen, an alkyl group or an alkoxy group; m is an integer from 1 to 5; x and y represent the proportion of respective units, and neither x nor y is 0; and R1 denotes a methyl, ethyl, or isopropyl group; a production method thereof, and a polymer optical waveguide pattern formation method using the same.

The polymer-based waveguide device for light amplifier and laser waveguide includes base body, inner polymer coating on the base body, channel waveguide set on the inner polymer coating and outer polymer coating covering the inner polymer coating and the channel waveguide. The channel waveguide is made with at least one kind of RE metal ion doped composition capable of being excited to generate laser. The preparation process of the waveguide device includes the steps of: making a base body; painting the inner polymer coating on the base body and drying to cure; painting the second polymer with dissolved RE metal ion doped composition and selectively curing and etching to form the channel waveguide; and painting outer polymer coating and drying to cure. The waveguide device has excellent light amplifying and transmitting function.

Method of fabricating a microfluidic device by means of inducing internal cracks in fused silica employing a picosecond laser beam, firstly utilizing irradiation of a focused temporally controlled picosecond laser beam in fused silica to generate a spatially selective modification region including randomly oriented nanocracks, then employing chemical etching to remove the irradiated area and obtain a hollow and connected three-dimensional microstructure, thereby achieving three-dimensional fabrication of microchannel structures inside the fused silica. The method can realize polarization insensitive three-dimensional uniform etching by regulating the pulse width of the picosecond laser beam, and has high chemical etch rate and selectivity, applicable for fabrication of large-sized three-dimensional microfluidic systems, high-precision 3D glass printing, etc.

The invention provides a device for increasing extinction ratio. The device comprises a DML, an isolator and an optical fiber, and further comprises a first filter plate, a lens, a second filter plate and a photodiode component, wherein the isolator is arranged between the DML and the first filter plate; the lens is arranged between the optical fiber and the second filter plate; the first filter plate is used for enhancing the extinction ratio of optical signals output by the DML; the lens is used for ensuring that an included angle is formed between the optical signals and the central optical axis of the lens, so as to enable the second filter plate to reflect the optical signals to the optical fiber to realize transmission; the second filter plate is used for performing upper and downlink light splitting on the optical signals; the photodiode component comprises a first photodiode and a second photodiode; the first photodiode is used for detecting the state of the optical signals in the downlink and feeding back the state to the DML; the second photodiode is used for performing photovoltaic conversion on the optical signals in the uplink, so that by adoption of the device, the extinction ratio is increased, and meanwhile the insertion loss and the polarization dependence in an optical path are reduced.

The invention provides a side-polished polymer temperature sensing fiber. The side-polished polymer temperature sensing fiber is utilized to manufacture a fiber evanescent wave sensor, and on the basis of the evanescent wave coupling resonance principle and through utilization of an arc structure of a single-mode fiber, part of waves in transverse-magnetic polarized light in specific incident light are coupled into a planar waveguide formed by a polymer coating to a greater extent, so that evanescent waves are formed. The refractive index of a planar waveguide SiO2 coating is equal to the refractive index of a coating of the single-mode fiber, and polarization dependence caused by a planar waveguide birefringence structure is weakened. The invention also provides a fiber temperature sensor applying the above side-polished polymer temperature sensing fiber. The fiber temperature sensor has the advantages of being simple and fast in manufacturing technique, exhibiting good stability, good repeatability, high sensitivity and low temperature output, etc. Meanwhile, the sensor overcomes the disadvantages that a conventional electrochemical temperature sensor does not resist corrosion or electric radiation, etc.