# US 6,720,582 B2 · Semiconductor laser diode module > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,720,582 B2 - Document ID: US6720582B2 - Status: Granted - Kind: B2 - Application number: 09/867,402 - Filed: 2001-05-31 - Published: 2002-01-24 - Granted: 2004-04-13 - Earliest claimed: 2000-05-31 - Assignees: Furukawa Electric Co., Ltd. - Inventors: Jun Miyokawa; Yuichiro Irie; Etsuji Katayama; Kaoru Sekiguchi; Kiyokazu Tateno - Web page: https://patentgrep.com/patent/US6720582B2 ## CPC - G02B 6/4201: {Packages, e.g. shape, construction, internal or external details} - G02B 6/4202: {for coupling an active element with fibres without intermediate optical elements, e.g. fibres with plane ends, fibres with shaped ends, bundles} - G02B 6/4208: {using non-reciprocal elements or birefringent plates, i.e. quasi-isolators (optical isolators per se G02F1/093, G02F1/0955)} - G02B 6/4237: {Welding} - G02B 6/4248: {Feed-through connections for the hermetical passage of fibres through a package wall (see provisionally also G02B6/4428)} - G02B 6/4203: {Optical features} - G02B 6/4204: {the coupling comprising intermediate optical elements, e.g. lenses, holograms (encapsulated active devices H01S5/02208)} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract A laser diode module in which a laser diode and an optical fiber are optically coupled with each other efficiently irrespective of an ambient temperature change within the laser diode module. The laser diode module includes a laser diode, an optical system, an optical system mounting member supporting at least a portion of the optical system, a laser diode mounting member, and a bottom plate supporting the laser diode, the optical system, the optical system mounting member, and the laser diode mounting member. The optical system receives and transmits a beam emitted from the laser diode through a lens portion to an optical fiber. The optical system mounting member is attached to the laser diode mounting member. The laser diode module preferably includes a thermo module having a first plate member attached to the laser diode mounting member. The laser diode mounting member is preferably formed of material having an expansion coefficient in a range between an expansion coefficient of the optical system mounting member and an expansion coefficient of the first plate member. ## Claims ### Claim 1 A laser diode module comprising: a laser diode; an optical system including an optical fiber and a lens portion, said optical system being configured to receive and transmit a beam emitted from said laser diode through said lens portion to said optical fiber along an optical axis; an optical system mounting member configured to support at least a portion of said optical system; a laser diode mounting member configured to support said laser diode, said optical system mounting member being attached to said laser diode mounting member; a bottom plate configured to support said laser diode, said optical system, said optical system mounting member, and said laser diode mounting member; and a temperature control device thermally connected to said laser diode by said laser diode mounting member, said temperature control device being attached to said bottom plate, wherein said optical system mounting member is not in direct contact with said temperature control device. ### Claim 2 (depends on 1) The laser diode module according to claim 1, wherein said temperature control device is a thermo module, said thermo module having a first plate member attached to said laser diode mounting member, a second plate member attached to said bottom plate, and a peltier element positioned between said first plate member and said second plate member. ### Claim 3 (depends on 2) The laser diode module according to claim 2, wherein said laser diode mounting member is formed of material having a linear expansion coefficient in a range between a linear expansion coefficient of said optical system mounting member and a linear expansion coefficient of said first plate member of said thermo module. ### Claim 4 (depends on 2) The laser diode module according to claim 2, wherein said optical system mounting member has a thermal conductivity lower than a thermal conductivity of said laser diode mounting member. ### Claim 5 (depends on 2) The laser diode module according to claim 2, wherein said first plate member is made of aluminum oxide. ### Claim 6 (depends on 1) The laser diode module according to claim 1, wherein said optical fiber has a portion contained within a holder, and wherein said optical system mounting member comprises a holder mounting member attached to said holder. ### Claim 7 (depends on 1) The laser diode module according to claim 1, wherein said laser diode mounting member is made of copper tungsten 10. ### Claim 8 (depends on 1) The laser diode module according to claim 1, wherein said optical system mounting member is made of an Fe—Ni—Co alloy. ### Claim 9 (depends on 1) The laser diode module according to claim 1, wherein said laser diode is mounted on a laser diode bonding portion, said laser diode bonding portion being mounted on said laser diode mounting member. ### Claim 10 (depends on 1) The laser diode module according to claim 1, wherein said lens portion is a discrete lens supported by said optical system mounting member. ### Claim 11 (depends on 10) The laser diode module according to claim 10, wherein: said optical system further comprises an optical isolator supported by said optical system mounting member; and said optical system is configured to receive and transmit the beam emitted from said laser diode through said discrete lens and said optical isolator to said optical fiber along said optical axis. ### Claim 12 (depends on 11) The laser diode module according to claim 11, wherein: said discrete lens is connected to a holder; and said optical system mounting member comprises a holder mounting member supporting said holder. ### Claim 13 (depends on 12) The laser diode module according to claim 12, wherein said optical isolator is mounted to said holder mounting member. ### Claim 14 (depends on 11) The laser diode module according to claim 11, wherein said optical fiber is supported by said bottom plate. ### Claim 15 (depends on 14) The laser diode module according to claim 14, wherein: said optical system further comprises a second lens supported by said bottom plate; and said optical system is configured to receive and transmit the beam emitted from said laser diode through said discrete lens, said optical isolator, and said second lens to said optical fiber along said optical axis. ### Claim 16 (depends on 15) The laser diode module according to claim 15, further comprising a package including said bottom plate, said package being configured to support said second lens and said optical fiber. ### Claim 17 (depends on 10) The laser diode module according to claim 10, wherein said laser diode mounting member is fixed on said bottom plate via a thermo module. ### Claim 18 (depends on 1) The laser diode module according to claim 1, wherein: said laser diode mounting member is made of a material having a thermal conductivity of at least 150 W/mK; and said optical system mounting member is made of a material having a thermal conductivity of at most 50 W/mK. ### Claim 19 (depends on 1) The laser diode module according to claim 1, wherein said optical system mounting member is made of a material having a Young's modulus of at least 15×103 kg/mm2. ### Claim 20 (depends on 1) The laser diode module according to claim 1, wherein said optical system mounting member is made of a material that is substantially non-magnetic. ### Claim 21 A semiconductor laser diode module comprising: a laser diode; an optical system including an optical fiber and a lens portion, said optical system being configured to receive and transmit a beam emitted from said laser diode through said lens portion to said optical fiber along an optical axis; a fastening means for supporting at least a portion of said optical system; a base configured to support said fastening means and said laser diode; a bottom plate configured to support said laser diode, said optical system, said fastening means, and said base, wherein said base includes a laser diode mounting member and a fastening means mounting member, said laser diode mounting member having a laser diode mounting region configured to mount said laser diode, said fastening means mounting member being mounted to said laser diode mounting member at a position other than said laser diode mounting region; and a temperature control device thermally connected to said laser diode by said laser diode mounting member, said temperature control device being attached to said bottom plate, wherein said fastening means mounting member is not in direct contact with said temperature control device. ### Claim 22 (depends on 21) The semiconductor laser diode module according to claim 21, wherein said temperature control device comprises: a thermo module mounted on said bottom plate, said thermo module having a base side plate member on which said base is mounted, wherein said laser diode mounting member is formed of a material having a linear expansion coefficient in a range between a linear expansion coefficient of said fastening means mounting member and a linear expansion coefficient of said base side plate member of said thermo module. ### Claim 23 (depends on 22) The semiconductor laser diode module according to claim 22, wherein said fastening means mounting member has a thermal conductivity lower than a thermal conductivity of said laser diode mounting member. ### Claim 24 (depends on 22) The semiconductor laser diode module according to claim 22, further comprising a package including said bottom plate, said package being configured to accommodate therein said laser diode, said optical system, said fastening means, said base, and said thermo module. ### Claim 25 (depends on 22) The semiconductor laser diode module according to claim 22, wherein said thermo module further includes a bottom plate side plate member and a peltier element positioned between said base side plate member and said bottom plate side plate member. ### Claim 26 (depends on 22) The semiconductor laser diode module according to claim 22, wherein said base projects in a direction parallel to an optical axis of said optical system from an end portion on an optical fiber mounting side of said thermo module. ### Claim 27 (depends on 26) The semiconductor laser diode module according to claim 26, wherein said fastening means mounting member projects in a direction parallel to said optical axis from an end portion on an optical fiber mounting side of said laser diode mounting member. ### Claim 28 (depends on 27) The semiconductor laser diode module according to claim 27, wherein said laser diode mounting member has a reinforcement portion for mechanically reinforcing said fastening means located at a position closest to said laser diode, and wherein said reinforcement portion has a lower surface that is out of contact with said thermo module. ### Claim 29 (depends on 21) The semiconductor laser diode module according to claim 21, wherein said lens portion has a fiber lens formed on said optical fiber, and wherein said fiber lens has a tip end side arranged to oppose a light emitting facet of said laser diode. ### Claim 30 (depends on 29) The semiconductor laser diode module according to claim 29, wherein said fiber lens is an anamorphic lens. ### Claim 31 (depends on 21) The semiconductor laser diode module according to claim 21, wherein said fastening means is made of an Fe—Ni—Co alloy. ### Claim 32 (depends on 21) The semiconductor laser diode module according to claim 21, wherein said fastening means mounting member is made of an Fe—Ni—Co alloy. ### Claim 33 (depends on 21) The semiconductor laser diode module according to claim 21, wherein said lens portion is a discrete lens supported by said fastening means. ### Claim 34 (depends on 33) The semiconductor laser diode module according to claim 33, wherein: said optical system further comprises an optical isolator supported by said fastening means mounting member; said optical system further comprises a second lens supported by said bottom plate; and said optical system is configured to receive and transmit the beam emitted from said laser diode through said discrete lens, said optical isolator, and said second lens to said optical fiber along said optical axis. ### Claim 35 (depends on 34) The semiconductor laser diode module according to claim 34, further comprising a package including said bottom plate, said package being configured to support said second lens and said optical fiber. ### Claim 36 (depends on 21) The semiconductor laser diode module according to claim 21, wherein said laser diode mounting member is fixed on said bottom plate via a thermo module. ### Claim 37 (depends on 21) The semiconductor laser diode module according to claim 21, wherein: said laser diode mounting member is made of a material having a thermal conductivity of at least 150 W/mK; and said fastening means mounting member is made of a material having a thermal conductivity of at most 50 W/mK. ### Claim 38 (depends on 21) The semiconductor laser diode module according to claim 21, wherein said fastening means mounting member is made of a material having a Young's modulus of at least 15×103 kg/mm2. ### Claim 39 (depends on 21) The semiconductor laser diode module according to claim 21, wherein said fastening means mounting member is made of a material that is substantially non-magnetic.