# US 9,519,151 B2 · Optical multiplexer and transmitter optical subassembly > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,519,151 B2 - Document ID: US9519151B2 - Status: Granted - Kind: B2 - Application number: 14/565,836 - Filed: 2014-12-10 - Published: 2015-06-25 - Granted: 2016-12-13 - Earliest claimed: 2013-12-24 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Xueming Zhang; Zhengwen Wan - Web page: https://patentgrep.com/patent/US9519151B2 ## CPC - G02B 27/14: operating by reflection only - G02B 6/2713: {cascade of polarisation selective or adjusting operations} - G02B 6/2773: {Polarisation splitting or combining} - G02B 6/2938: {for multiplexing or demultiplexing, i.e. combining or separating wavelengths, e.g. 1xN, NxM} - G02B 27/126: {The splitting element being a prism or prismatic array, including systems based on total internal reflection} - G02B 27/283: {used for beam splitting or combining} - G02F 1/093: {used as non-reciprocal devices, e.g. optical isolators, circulators (G02F1/0955 takes precedence)} - H04J 14/00: Optical multiplex systems - H04J 14/08: Time-division multiplex systems - G02B 6/272: {comprising polarisation means for beam splitting and combining} - G02B 6/2746: {comprising non-reciprocal devices, e.g. isolators, FRM, circulators, quasi-isolators (magneto-optic non-reciprocal devices G02F1/093)} - H04J 14/06: Polarisation multiplex systems - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS - H04J: MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L5/00; systems for the simultaneous or sequential transmission of more than one television signal H04N7/08; in exchanges H04Q11/00; stereophonic systems H04S) ## Abstract An optical multiplexer and a transmitter optical subassembly are provided that relate to the field of optics communications. A light-combining part is formed by using at least one light combiner that can combine two beams of light into one beam of light, and at least two levels of light-combining parts are used to constitute an optical multiplexer, so that 2N beams of light are combined into one beam by using N level of light-combining parts, thereby reducing a package size and packaging loss, and reducing the complexity of a manufacturing process. ## Claims ### Claim 1 An optical multiplexer, comprising: at least two levels of light-combining parts, wherein each level of light-combining parts comprises light combiners whose number is half the number of beams of input light of the each level, wherein each light combiner is configured to combine two beams of light into one beam, and wherein the optical multiplexer comprises at least two different types of light combiners; collimation lenses, wherein a number of the collimation lenses is the same as a number of light sources, and wherein each of the collimation lenses is disposed between a light source and a first level of light-combining parts; and a focusing lens disposed behind a light outlet of a last level of light-combining parts. ### Claim 2 (depends on 1) The optical multiplexer according to claim 1, wherein one type of the at least two different types of light combiners comprises a polarization beam combiner (PBC) light combiner. ### Claim 3 (depends on 2) The optical multiplexer according to claim 2, wherein the PBC light combiner comprises: a PBC configured to combine light input through a first light inlet and light input through a second light inlet into one beam, wherein the first light inlet directly faces first incident light of the PBC light combiner; a half wave plate whose optical axis is disposed at a 45-degree angle to a polarization direction of second incident light of the PBC light combiner, and a reflector configured to reflect light output by the half wave plate to the second light inlet of the PBC. ### Claim 4 (depends on 2) The optical multiplexer according to claim 2, wherein another type of the at least two different types of light combiners comprises a light-splitting prism light combiner, and wherein the light-splitting prism light combiner comprises: a light-splitting prism configured to combine light input through a first light inlet and light input through a second light inlet into one beam, wherein the first light inlet directly faces first incident light of the light-splitting prism light combiner; a reflector configured to reflect second incident light of the light-splitting prism light combiner to the second light inlet of the light-splitting prism; and a beam absorber disposed on an opposite side of the second light inlet of the light-splitting prism and configured to absorb light obtained after the light input through the second light inlet is transmitted by the light-splitting prism and light obtained after the light input through the first light inlet is reflected by the light-splitting prism. ### Claim 5 (depends on 4) The optical multiplexer according to claim 4, wherein the light-splitting prism is a 3 decibel (dB) light-splitting prism. ### Claim 6 (depends on 1) The optical multiplexer according to claim 1, wherein light combiners in one level of light-combining parts are the same. ### Claim 7 (depends on 1) The optical multiplexer according to claim 1, wherein the optical multiplexer further comprises at least one isolator disposed between two levels of light-combining parts and configured to isolate light that is reflected from a light output direction. ### Claim 8 (depends on 7) The optical multiplexer according to claim 7, wherein the at least one isolator is a polarization-related isolator when a next level of light-combining parts comprises a PBC light combiner. ### Claim 9 (depends on 1) The optical multiplexer according to claim 1, wherein one type of the at least two different types of light combiners comprises a light-splitting prism light combiner. ### Claim 10 A transmitter optical subassembly, comprising: an optical multiplexer, wherein the optical multiplexer comprises: at least two levels of light-combining parts, wherein each level of light-combining parts comprises light combiners whose number is half the number of beams of input light of the each level, wherein each light combiner is configured to combine two beams of light into one beam, and wherein the optical multiplexer comprises at least two different types of light combiners; collimation lenses, wherein a number of the collimation lenses is the same as the number of light sources, each of the collimation lenses being disposed between a light source and a first level of light-combining parts; a focusing lens disposed behind a light outlet of a last level of light-combining parts; a laser chip that is used as a light source, wherein the laser chip is connected to an input end of the optical multiplexer; and a ceramic ferrule that is used for coupling output, wherein the ceramic ferrule is connected to an output end of the optical multiplexer. ### Claim 11 (depends on 10) The transmitter optical subassembly according to claim 10, comprising a photoelectric detector connected to the laser chip and configured to monitor transmitted power of the laser chip. ### Claim 12 (depends on 10) The transmitter optical subassembly according to claim 10, wherein one type of the at least two different types of light combiners is a polarization beam combiner (PBC) light combiner. ### Claim 13 (depends on 12) The transmitter optical subassembly according to claim 12, wherein the PBC light combiner comprises: a PBC configured to combine light input through a first light inlet and light input through a second light inlet into one beam, wherein the first light inlet directly faces first incident light of the PBC light combiner, a half wave plate, whose optical axis is disposed at a 45-degree angle to a polarization direction of second incident light of the PBC light combiner; and a reflector configured to reflect light output by the half wave plate to the second light inlet of the PBC. ### Claim 14 (depends on 12) The transmitter optical subassembly according to claim 12, wherein another type of the at least two different types of light combiners comprises a light-splitting prism light combiner, and wherein the light-splitting prism light combiner comprises: a light-splitting prism configured to combine light input through a first light inlet and light input through a second light inlet into one beam, wherein the first light inlet directly faces first incident light of the light-splitting prism light combiner; a reflector configured to reflect second incident light of the light-splitting prism light combiner to the second light inlet of the light-splitting prism; and a beam absorber disposed on an opposite side of the second light inlet of the light-splitting prism and configured to absorb light obtained after the light input through the second light inlet is transmitted by the light-splitting prism and light obtained after the light input through the first light inlet is reflected by the light-splitting prism. ### Claim 15 (depends on 14) The transmitter optical subassembly according to claim 14, wherein the light-splitting prism is a 3 decibel (dB) light-splitting prism. ### Claim 16 (depends on 10) The transmitter optical subassembly according to claim 10, wherein light combiners in one level of light-combining parts are the same. ### Claim 17 (depends on 10) The transmitter optical subassembly according to claim 10, wherein the optical multiplexer further comprises at least one isolator disposed between two levels of light-combining parts and configured to isolate light that is reflected from a light output direction. ### Claim 18 (depends on 17) The transmitter optical subassembly according to claim 17, wherein the at least one isolator is a polarization-related isolator when a next level of light-combining parts comprises a PBC light combiner. ### Claim 19 (depends on 10) The transmitter optical subassembly according to claim 10, wherein one type of the at least two different types of light combiners comprises a light-splitting prism light combiner.