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Researchers Submit Patent Application, "Receiver Optical Module Installing Optical Demultiplexer and Method to Produce Optical Demultiplexer", for...

June 4, 2014



Researchers Submit Patent Application, "Receiver Optical Module Installing Optical Demultiplexer and Method to Produce Optical Demultiplexer", for Approval

By a News Reporter-Staff News Editor at Electronics Newsweekly -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventors Fujimura, Yasushi (Yokohama-shi, JP); Kawamura, Masanobu (Yokohama-shi, JP), filed on November 11, 2013, was made available online on May 22, 2014.

The patent's assignee is Sumitomo Electric Industries, Ltd.

News editors obtained the following quote from the background information supplied by the inventors: "The present application relates to a receiver optical module that receives a wavelength multiplexed light and outputs a plurality of electrical signals.

"As an amount of information transmitted on the communication network increases, an optical transmitter/receiver module has been requested to be operable in the transmission speed exceeding 40 Gbps, sometimes reaching 100 Gbps. Such an optical module inevitably installs therein a plural active devices, typically a semiconductor laser diode (hereafter denoted as LD) and/or a semiconductor photodiode (hereafter denoted as PD) to perform the wavelength division multiplexing function.

"In order to realize the transmission speed of 40 Gbps, a transmitter installs therein four sets of transmitter optical modules each operable in 10 Gbps and an optical multiplexer to multiplex optical signals coming from the respective transmitter modules; while a receiver installs an optical demultiplexer to demultiplex an optical signal containing four wavelengths into four independent optical signals depending on the wavelengths thereof and four sets of receiver optical subassemblies (ROSA) each receiving the demultiplexed optical signal.

"In another aspect for an optical communication apparatus, an eager request to make the apparatus in compact has been continuously raised. As far as in a field of an optical transceiver, new standards of, for instance, CFP2, CFP4, QSFP+, and so on to make the outer dimensions of a housing in compact compared to the currently popular standard CFP have been proposed. In such a compact housing, spaces allocated to transmitter/receiver modules are further narrowed. For instance, the new standard defines the space for a receiver module with a width narrower than 7 mm. One practical solution for subjects above described is that a receiver module installs therein an optical demultiplexer type of the multilayered dielectric films. Japanese Patent Application Laid-Open publication Nos. JP-2009-198958A and JP-2011-209367A have disclosed such an optical demultiplexer."

As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventors' summary information for this patent application: "An aspect of the present application relates to a receiver optical module that receives an input optical signal containing signals each having a specific wavelength different from others. The receiver optical module comprises an optical demultiplexer and a PD. The optical demultiplexer includes a body to receive the input optical signal and a base substrate providing a wavelength selective filter on one surface thereof. The wavelength selective filter, which is attached to the body, transmits only one of signals depending on the wavelength thereof. The PD receives one of signals selected by the wavelength selective filter. A feature of the optical demultiplexer is that the base substrate has a plane shape of a parallelogram with two sides opposite to each other extending substantially in parallel to an optical axis of one of signals transmitting in the base substrate.

"The base substrate has a height greater than 0.3 mm, preferably greater than 1 mm, along the optical axis. Even in such an arrangement of the base substrate, one of the signals is output from a center of a surface of the base substrate.

"The receiver optical module further includes an optical reflector, a support, and a package. The package, which has a box shape with a bottom, encloses the optical demultiplexer, the optical reflector, the support, and the PD therein. The PD is mounted on the bottom of the package, while, the optical demultiplexer and the optical reflector are mounted on the support in upside down. The optical reflector reflects signals output from the optical demultiplexer toward the PD in substantially right angle.

"Another aspect of the present application relates to a method to produce an optical demultiplexer. The method includes steps of: (a) preparing a first base material for a body, second base materials for base substrates, and a third base material for a reflector, wherein the second base materials have a feature that they have a cross section of a parallelogram; (b) depositing wavelength selective filters on respective surfaces of the second base materials and a reflective film on a surface of the third base material; © attaching the third base material to one surface of the first base material such that the reflective film faces the first base material and attaching the second base materials to another surface of the first base material opposite to the one surface such that respective wavelength selective filters face the another surface and second base materials form no gaps therebetween; and (d) cutting the first base material with the second base materials and the third base material so as to obtain a plurality of wavelength demultiplexers each having an arrangement same with others.

BRIEF DESCRIPTION OF THE DRAWINGS

"The foregoing and other purposes, aspects and advantages will be better understood from the following detailed description of various embodiments with reference to the drawings, in which:

"FIG. 1A is a perspective view showing an inside of a receiver optical module, and FIG. 1B is a plan view of an inside of the receiver optical module;

"FIG. 2A functionally illustrates an optical demultiplexer and a reflector installed in the receiver optical module shown in FIG. 1A, and FIG. 2B magnifies a first portion of the optical demultiplexer shown in FIG. 2A;

"FIGS. 3A to 3C show modifications of the optical demultiplexer shown in FIG. 2A;

"FIGS. 4A to 4C show modifications of an installation of the optical demultiplexer and the reflector;

"FIGS. 5A to 5D show a process to produce an optical demultiplexer; and

"FIG. 6A is a plan view of an inside of a comparable optical module, and FIG. 6B magnifies a primary portion of the optical demultiplexer shown in FIG. 6B."

For additional information on this patent application, see: Fujimura, Yasushi; Kawamura, Masanobu. Receiver Optical Module Installing Optical Demultiplexer and Method to Produce Optical Demultiplexer. Filed November 11, 2013 and posted May 22, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=3442&p=69&f=G&l=50&d=PG01&S1=20140515.PD.&OS=PD/20140515&RS=PD/20140515

Keywords for this news article include: Electronics, Semiconductor, Sumitomo Electric Industries Ltd.

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Source: Electronics Newsweekly


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