Optical multi/demultiplexer, optical multi/demultiplexing method, and optical filter
Inactive Publication Date: 2005-05-05
MITSUBISHI RAYON CO LTD
View PDF4 Cites 4 Cited by
Summary
Abstract
Description
Claims
Application Information
AI Technical Summary
This helps you quickly interpret patents by identifying the three key elements:
Problems solved by technology
Method used
Benefits of technology
Benefits of technology
[0019] In the optical filter having the above structure, the wavelength of the monochromatic light to be introduced into the monochromatic connecting section can be varied by varying-the temperature of the light transmission section. Thus, a desired wavelength of light can be selectively picked up with a simple structure.
Problems solved by technology
Thus, they involve a high-cost problem due to increase in the number of components and the number of assembling steps, and the need for complicated adjustments.
Further, the optical demultiplexer using a star coupler involves a problem of degradation in output light intensity due to branching of a multiplexed light through the star coupler.
However, the optical filter and the optical switch having the above-described optical waveguide is not suited for mass production due to its complicated production process.
Further, since it is required in the process of forming the grating to periodically form notches in a core or clad with a high precision in the order of several microns or more, the cost is increased.
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more
Image
Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
Click on the blue label to locate the original text in one second.
Reading with bidirectional positioning of images and text.
Smart Image
Examples
Experimental program
Comparison scheme
Effect test
first embodiment
[0036] As described later, the light demultiplexing section 2 in the first embodiment is used to multiplex and demultiplex light by utilizing the wavelength dispersion characteristic of the light demultiplexing section 2 such that it has different refractive index profiles with respect to each of different wavelengths of light. For this purpose, the light demultiplexing section 2 is preferably made of materials largely different in Abbe number to increase the difference in refractive index profile with respect to each of different wavelengths of light. The difference in Abbe number is preferably 20 or more, more preferably 50 or more. While it is preferable to set the difference in Abbe number as large as possible, it is typically set at 80 or less.
[0037] The optical demultiplexer 1 includes an incidence-side connecting section 8 serving as a wavelength-multiplexed-light connecting section for allowing an optical fiber 6 transmitting a wavelength multiplexed light 4 to be connected ...
second embodiment
[0059] In the second embodiment, a Peltier element is used as the temperature controller 62. While the Peltier element is desirable because it can effectively perform heating and cooling, any other suitable heating means, such as electric heater, or cooling means may be used.
[0060] Preferably, in order to uniformly heat or cool the light transmission section 54, the optical filter 51 particularly the light transmission section 54, is sealed with another resin, or the light transmission section 54 is contained in the temperature controller 62 formed in a tubular shape.
[0061] The light transmission section 54 has an substantially cylindrical shape, and serves as a graded index type light transmission section whose refractive index is continuously reduced in the direction from the axis c to the periphery thereof In the second embodiment, the refractive index n of the light transmission section 54 has a distribution approximated by the following formula (1):
n(r)=n0×(1−g2×r2 / 2) (1)
...
third embodiment
[0083] In the third embodiment, under the above temperature condition, the monochromatic light of the wavelength λ1=1285.4 nm, and the monochromatic light of the wavelength λ2=1523.6 nm are emitted, respectively, from the positions r21=0.01 mm and r22=0.00 mm, and only the monochromatic light 168 of the wavelength λ2 is entered into an outgoing optical fiber 160.
[0084]FIG. 11 is a graph showing the temperature dependence of the refractive index profile of the light transmission section 154. As seen in FIG. 11, in the light transmission section 154, the temperature dependence coefficient of the refractive index profile constant is 6.0×10−5 / ° C. Thus, if the light transmission section 154 is set at a temperature of 70° C., the refractive index profile constants g1 and g2 for the wavelengths λ1 and λ2 are varied, respectively, to 0.540 and 0.537, and the distances r2 and r22 between the axis c and each of the wavelengths λ1 and λ2 are varied, respectively, to 0.00 mm and −0.01 mm. Thus...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More
PUM
Login to View More
Abstract
Disclosed is an optical multi / demultiplexer, which comprises a graded index type light transmission section whose refractive index is continuously reduced in the direction from the center to the periphery thereof, a wavelength-multiplexed-light connecting section disposed at one of the axial ends of the light transmission section, and at least one monochromatic light connecting section disposed at the other axial end of the light transmission section. The wavelength-multiplexed-light connecting section and the monochromatic light connecting section are disposed relative to the light transmission section in such a positional relationship that a monochromatic light included in a wavelength multiplexed light entered from the wavelength-multiplexed-light connecting section into the one end of the light transmission section is emitted from the other end of the light transmission section at a position where the monochromatic light connecting section is disposed. The present invention can provide an optical multi / demultiplexer having a reduced number of components and allowing the number of assembling steps to be reduced while eliminating the need for complicated adjustments.
Description
TECHNICAL FIELD [0001] The present invention relates to an optical multi / demultiplexer, an optical multi / demultiplexing method, and an optical filter (optical switch) capable of picking up a light having a specific wavelength. BACKGROUND ART [0002] Late years, in connection with the advent of the multimedia information society with the popularization of portable telephones, motion picture communications, electronic commerce and others, the transmission volume of communication networks is being continuously increased. As a technique capable of sending and receiving a large amount of information communication at a lower cost, there has been employed a transmission system based on a wavelength division multiplexingtransmission technology comprising giving different informations respectively, to lights different in wavelength, multiplexing the lights with the different wavelengths, and transmitting the wavelength multiplexed light through a single optical fiber. This transmission syste...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More
Application Information
Patent Timeline
Application Date:The date an application was filed.
Publication Date:The date a patent or application was officially published.
First Publication Date:The earliest publication date of a patent with the same application number.
Issue Date:Publication date of the patent grant document.
PCT Entry Date:The Entry date of PCT National Phase.
Estimated Expiry Date:The statutory expiry date of a patent right according to the Patent Law, and it is the longest term of protection that the patent right can achieve without the termination of the patent right due to other reasons(Term extension factor has been taken into account ).
Invalid Date:Actual expiry date is based on effective date or publication date of legal transaction data of invalid patent.
Login to View More 
Login to View More