# US 9,520,948 B2 · Optical transmission device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,520,948 B2 - Document ID: US9520948B2 - Status: Granted - Kind: B2 - Application number: 14/615,603 - Filed: 2015-02-06 - Published: 2015-09-17 - Granted: 2016-12-13 - Earliest claimed: 2014-03-11 - Assignees: Fujitsu Optical Components Limited - Applicants: Fujitsu Optical Components Limited - Inventors: Masaharu Doi; Yoshinobu Kubota; Yoshitada Kawashima; Teruhiro Kubo - Web page: https://patentgrep.com/patent/US9520948B2 ## CPC - H04B 10/501: {Structural aspects} - G02B 6/34: utilising prism or grating {(G02B6/293 takes precedence)} - H04B 10/506: {Multiwavelength transmitters} - G02F 1/133607: {the light controlling member including light directing or refracting elements, e.g. prisms or lenses} - H04B: TRANSMISSION - 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 ## Abstract A substrate is a substrate on which a first optical modulator and a second optical modulator are arranged in parallel along a width direction. A first prism moves, to a side opposite to the second optical modulator along the width direction of the substrate, an optical path of the first output light and the second output light that are obtained by light of the first wavelength being modulated by the first optical modulator. A second prism is arranged at a position away from the first prism along a longitudinal direction of the substrate and moves, to a side opposite to the first modulator along the width direction of the substrate, an optical path of the third output light and the fourth output light that are obtained by the light of the second wavelength being modulated by the second optical modulator. ## Claims ### Claim 1 An optical transmission device comprising: a substrate on which a first optical modulator that modulates first light split off from light of a first wavelength, a second optical modulator that modulates second light split off from the light of the first wavelength, a third optical modulator that modulates third light split off from light of a second wavelength, and a fourth optical modulator that modulates fourth light split off from the light of the second wavelength are arranged in parallel along a width direction; a first prism that moves, to a side opposite to the third optical modulator and the fourth optical modulator along the width direction of the substrate, an optical path of first output light obtained by the first light being modulated by the first optical modulator and an optical path of second output light obtained by the second light being modulated by the second optical modulator; and a second prism that is arranged at a position away from the first prism along a longitudinal direction of the substrate and that moves, to a side opposite to the first modulator and the second optical modulator along the width direction of the substrate, an optical path of third output light obtained by the third light being modulated by the third optical modulator and an optical path of fourth output light obtained by the fourth light being modulated by the fourth optical modulator. ### Claim 2 (depends on 1) The optical transmission device according to claim 1, wherein the second prism is arranged at the position away from the first prism along the longitudinal direction of the substrate so that the second prism is overlapped with a part of the first prism when viewed from the longitudinal direction of the substrate. ### Claim 3 (depends on 1) The optical transmission device according to claim 1, wherein a length of the first prism in the width direction of the substrate is different from a length of the second prism in the width direction of the substrate. ### Claim 4 (depends on 1) The optical transmission device according to claim 1, further comprising: a first and a second collimator lenses that are arranged between the substrate and the first prism and that collimate the first output light and the second output light, respectively; a third and a fourth collimator lenses that are arranged between the substrate and the second prism and that collimate the third output light and the fourth output light, respectively; and a collimator lens holding member that holds the first and the second collimator lenses and the third and the fourth collimator lenses along the width direction of the substrate in an array. ### Claim 5 (depends on 1) The optical transmission device according to claim 1, further comprising: a polarization beam combining unit that performs polarization combination on the first and the second output light or the third and the fourth output light emitted from the first prism or the second prism; a casing that accommodates therein the substrate, the first prism, the second prism, and the polarized wave combining unit; a focusing lens that collects light obtained by the first and the second output light or the third and the fourth output light being subjected to polarization combination; and a holding member that is secured outside the casing and that holds the focusing lens. ### Claim 6 (depends on 5) The optical transmission device according to claim 5, wherein the holding member is secured outside the casing by laser welding. ### Claim 7 (depends on 5) The optical transmission device according to claim 5, wherein the polarization beam combining unit includes a half-wave plate and a polarization beam combiner (PBC) prism. ### Claim 8 (depends on 5) The optical transmission device according to claim 5, wherein the polarization beam combining unit includes a half-wave plate and a uniaxial crystal. ### Claim 9 (depends on 1) The optical transmission device according to claim 1, further comprising: a casing that accommodates therein the substrate, the first prism and the second prism; a polarization beam combining unit that performs polarization combination on the first and the second output light or the third and the fourth output light output from the first prism or the second prism; a focusing lens that collects light obtained by the first and the second output light or the third and the fourth output light by being subjected to polarization combination; and a holding member that is secured outside the casing and that integrally holds the polarization beam combining unit and the focusing lens. ### Claim 10 (depends on 9) The optical transmission device according to claim 9, wherein the holding member is secured outside the casing by laser welding. ### Claim 11 (depends on 9) The optical transmission device according to claim 9, wherein the polarization beam combining unit includes a half-wave plate and a polarization beam combiner (PBC) prism. ### Claim 12 (depends on 9) The optical transmission device according to claim 9, wherein the polarization beam combining unit includes a half-wave plate and a uniaxial crystal. ### Claim 13 (depends on 1) The optical transmission device according to claim 1, further comprising: a first light source that emits light of the first wavelength; a second light source that emits light of the second wavelength; and a casing that accommodates the first light source and the second light source.