# US 9,435,711 B2 · OTDR light reflection structure of optical sub-assembly for transceivers of PON system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,435,711 B2 - Document ID: US9435711B2 - Status: Granted - Kind: B2 - Application number: 13/281,514 - Filed: 2011-10-26 - Published: 2013-05-02 - Granted: 2016-09-06 - Earliest claimed: 2011-10-26 - Assignees: Ezconn Corporation - Applicants: Chin-Tsung Wu - Inventors: Chin-Tsung Wu - Web page: https://patentgrep.com/patent/US9435711B2 ## CPC - G01M 11/3109: {Reflectometers detecting the back-scattered light in the time-domain, e.g. OTDR} - H04B 10/071: using a reflected signal, e.g. using optical time domain reflectometers [OTDR] - G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR - H04B: TRANSMISSION ## Abstract An OTDR light reflection structure of optical sub-assembly for transceivers of PON system includes: a retainer member installed at an end section of a light guide unit of the optical sub-assembly for transceivers and positioned in the optical sub-assembly for transceivers, the retainer member having a first end and a second end; and a light reflection filter affixed to the first end of the retainer member. When an OTDR emits a specific wavelength of light, the light reflection filter directly reflects the light back into the light guide unit. Then the signal is transmitted back to the OTDR for the OTDR to identify the subscriber position of the feedback signal and judge whether the optical fiber line is in a normal state. ## Claims ### Claim 1 An optical module comprising: a ferrule; and a light reflection filter on an optical path, wherein said light reflection filter is configured to reflect a wavelength of light, transmitted along said optical path to pass through a hole in said ferrule and then through an empty space to said light reflection filter, back along said optical path and allow permeability of another wavelength of said light. ### Claim 2 (depends on 1) The optical module of claim 1 further a retainer provided with a hole therein receiving and fitting with a portion of said ferrule, wherein said light reflection filter is affixed to said retainer. ### Claim 3 (depends on 2) The optical module of claim 2, wherein said retainer is integral as a single part. ### Claim 4 (depends on 2) The optical module of claim 2, wherein said retainer comprises a first restriction section and a second restriction section opposite to said first restriction section, wherein said light reflection filter is arranged between said first and second restriction sections. ### Claim 5 (depends on 4) The optical module of claim 4, wherein an interval is between said first restriction section and said light reflection filter. ### Claim 6 (depends on 2) The optical module of claim 2, wherein said light reflection filter has a surface facing said ferrule, wherein said surface of said light reflection filter has a periphery contacting said retainer. ### Claim 7 (depends on 1) The optical module of claim 1, wherein said light is configured to be incident to a surface of said light reflection filter at a substantially right angle to said surface. ### Claim 8 (depends on 1) The optical module of claim 1, wherein said ferrule has a first surface sloping relative to said optical path and facing a second surface of said light reflection filter, wherein said second surface is planar and substantially vertical to said optical path, wherein a first axial distance between said first and second surfaces and parallel with said optical path is greater than a second axial distance between said first and second surfaces and parallel with said optical path, wherein said first axial distance is opposite to said second axial distance with respect to said optical path. ### Claim 9 (depends on 1) The optical module of claim 1 further comprising a housing provided with a first opening therein having said optical path pass therethrough, and a light emitting unit received in a second opening in said housing, wherein said first and second openings are at opposite sides of said housing. ### Claim 10 (depends on 1) The optical module of claim 1 further comprising a housing provided with a first opening therein having said optical path pass therethrough, and a light detection unit received in a second opening in said housing, wherein said first and second openings are at neighboring sides of said housing. ### Claim 11 An optical module comprising: a ferrule; a retainer provided with a hole therein receiving and fitting with a portion of said ferrule; and a light filter affixed to said retainer and configured to allow permeability of a wavelength of light, wherein an optical path passes through a hole in said ferrule and then through an empty space to said light filter, wherein said ferrule has a first surface sloping relative to said optical path and facing a second surface of said light filter, wherein said second surface is substantially vertical to said optical path, wherein a first axial distance between said first and second surfaces and parallel with said optical path is greater than a second axial distance between said first and second surfaces and parallel with said optical path, wherein said first axial distance is opposite to said second axial distance with respect to said optical path. ### Claim 12 (depends on 11) The optical module of claim 11, wherein said second surface is planar. ### Claim 13 (depends on 11) The optical module of claim 11, wherein said second surface of said light filter has a periphery contacting said retainer. ### Claim 14 (depends on 11) The optical module of claim 11 further comprising a housing provided with a first opening therein having said optical path pass therethrough, and a light detection unit at a second opening in said housing, wherein said first and second openings are at neighboring sides of said housing. ### Claim 15 (depends on 11) The optical module of claim 11, wherein said retainer comprises a first restriction section and a second restriction section opposite to said first restriction section, wherein said light filter is arranged between said first and second restriction sections. ### Claim 16 (depends on 15) The optical module of claim 15 wherein an interval is between said first restriction section and said light reflection filter. ### Claim 17 (depends on 11) The optical module of claim 11 further comprising a housing provided with a first opening therein having said optical path pass therethrough, and a light emitting unit received in a second opening in said housing, wherein said first and second openings are at opposite sides of said housing. ### Claim 18 (depends on 11) The optical module of claim 11, wherein said retainer is integral as a single part. ### Claim 19 (depends on 11) The optical module of claim 11, wherein said light filter is configured to reflect another wavelength of light, transmitted along said optical path to pass through said hole in said ferrule and then through said empty space to said light filter, back along said optical path. ### Claim 20 (depends on 11) The optical module of claim 11 further comprising a housing provided with a first opening therein having said optical path pass therethrough, a first light detection unit at a second opening in said housing and a second light detection unit at a third opening in said housing, wherein said first and second openings are at neighboring sides of said housing, said first and third openings are at neighboring sides of said housing and said second and third openings are at opposite sides of said housing.