Lens array and optical module provided therewith

A lens array disposed between a first photoelectric conversion device for optical transmission and reception and an optical transmission body, which lens array is capable of optically coupling a plurality of light-emitting elements and an end face of the optical transmission body for optical transmission and is capable of optically coupling the end face of the optical transmission body and a plurality of second light-receiving elements for optical reception, in which first photoelectric conversion device the plurality of light-emitting elements, a plurality of first light-receiving elements, and the plurality of second light-receiving elements are formed, the plurality of first light-receiving elements each receiving, respectively, monitor light of each light-emitting element for monitoring light emitted from the plurality of light-emitting elements, and the plurality of second light-receiving elements receiving light transmitted through the optical transmission body, wherein:

• as the first photoelectric conversion device, a first photoelectric conversion device is disposed in which the plurality of light-emitting elements are formed in an array along a predetermined first direction, the plurality of first light-receiving elements are formed in an array along the first direction in a position on a second direction side perpendicular to the first direction and the optical transmission body side in relation to the row of light-emitting elements, and the plurality of second light-receiving elements are formed in an array along the first direction in a position on the second direction side and a side opposite to the optical transmission body in relation to the row of first light-receiving elements;
• and
• the lens array includes
• a first plate-shaped portion of a lens array main body that faces the first photoelectric conversion device in a third direction perpendicular to the first direction and the second direction;
• a second plate-shaped portion of the lens array main body that extends from an end portion of the first plate-shaped portion on the second direction side and the optical transmission body side towards the third direction and a side opposite to the first photoelectric conversion device, faces the end face of the optical transmission body in the second direction, and has a same refractive index as the first plate-shaped portion;
• a plurality of first lens faces that are formed in an array along the first direction on a first surface of the first plate-shaped portion facing the first photoelectric conversion device, each on which the light emitted of each of the plurality of light-emitting elements is incident;
• a plurality of second lens faces that are formed in an array along the first direction on a second surface of the second plate-shaped portion facing the end face of the optical transmission body, each emitting the light emitted of each of the plurality of light-emitting elements that has been incident on each of the plurality of first lens faces towards the end face of the optical transmission body;
• a plurality of third lens faces that are formed in an array along the first direction on the first surface in a position on the second direction side and the second plate-shaped portion side in relation to the row of first lens faces, each emitting the monitor light of each of the plurality of light-emitting elements that has been incident from an inner side of the first plate-shaped portion towards the plurality of first light-receiving elements;
• a plurality of fourth lens faces that are formed in an array along the first direction on the second surface in a position on the third direction side in relation to the row of second lens faces, on which transmitted light emitted from the end face of the optical transmission body is incident;
• a plurality of fifth lens faces that are formed in an array along the first direction on the first surface in a position on the second direction side and a side opposite to the second plate-shaped portion in relation to the row of third lens faces, each emitting the transmitted light that has been incident on each of the plurality of fourth lens faces towards the plurality of second light-receiving elements;
• a prism that is disposed to provide a predetermined gap on the third direction side and a side opposite to the first photoelectric conversion device in relation to a third surface on a side opposite to the first surface of the first plate-shaped portion, and forms an optical path of the light of each of the plurality of light-emitting elements after being incident on the plurality of first lens faces and an optical path of the transmitted light after being incident on the plurality of fourth lens faces;
• a first prism surface that forms a portion of a surface of the prism and is disposed in a position facing the third surface, on which the light of each of the plurality of light-emitting elements after being incident on the plurality of first lens faces is incident, and that transmits the transmitted light that has been incident from the inner side of the prism and after being incident on the plurality of fourth lens faces towards the plurality of fifth lens faces side;
• a second prism surface that forms a portion of the surface of the prism, has a predetermined slope angle in relation to the first prism surface to slope towards the second plate-shaped portion side as the second prism surface becomes farther from the first prism surface, totally reflects the light of each of the plurality of light-emitting elements that has been incident on the first prism surface towards the plurality of second lens faces, and totally reflects the transmitted light that has been incident from the inner side of the prism and after being incident on the plurality of fourth lens faces and before being incident on the first prism surface towards the first prism surface;
• a third prism surface that forms a portion of the surface of the prism, has a predetermined slope angle in relation to the first prism surface to slope towards a side opposite to the second plate-shaped portion as the third prism surface becomes farther from the first prism surface, on which the light of each of the plurality of light-emitting elements that has been totally reflected by the second prism surface is incident from the inner side of the prism, and on which the transmitted light after being incident on the plurality of fourth lens faces and before being incident on the second prism surface is incident and that transmits the incident transmitted light towards the second prism surface;
• a reflection/transmission layer formed on the third prism surface over a predetermined area including an incidence position of the light of each of the plurality of light-emitting elements and excluding an incidence position of the transmitted light, that reflects the light of each of the plurality of light-emitting elements that has been incident on the third prism surface towards the plurality of third lens faces as the monitor light of each of the plurality of light-emitting elements at a predetermined reflectance, and transmits the light of each of the plurality of light-emitting elements towards the plurality of second lens faces side at a predetermined transmittance;
• a first filler material that fills an area between the third surface and the first prism surface;
• and
• a second filler material that fills an area between the third prism surface and a fourth surface of the second plate-shaped portion on a side opposite to the second surface, and of which a refractive index difference with the prism is a predetermined value or less.

A lens array disposed between a photoelectric conversion device and an optical transmission body, which lens array is capable of optically coupling a plurality of light-emitting elements and an end face of the optical transmission body, in which photoelectric conversion device the plurality of light-emitting elements and a plurality of light-receiving elements are formed, the plurality of light-receiving elements each receiving, respectively, monitor light of each light-emitting element for monitoring light emitted from the plurality of light-emitting elements, wherein:

• as the photoelectric conversion device, a photoelectric conversion device is disposed in which a row of the light-emitting elements formed by the plurality of light-emitting elements being arrayed along a predetermined first direction are arrayed in parallel in a plurality of rows along a predetermined second direction that is perpendicular to the first direction, and a row of the light-receiving elements formed by the plurality of light-receiving elements being arrayed along the first direction in a position on the second direction side and the optical transmission body side in relation to the light-emitting elements in the plurality of rows are arrayed in parallel in a plurality of rows along the second direction;
• and
• the lens array includes
• a first lens member that faces the photoelectric conversion device in a third direction perpendicular to the first direction and the second direction;
• a second lens member that is bonded to the first lens member and faces the end face of the optical transmission body in the second direction;
• in which
• the first lens member includes
• first lens faces in a plurality of rows, in which a plurality of first lens faces are formed in an array along the first direction on a surface facing the photoelectric conversion device and the first lens faces are formed in a plurality of rows in parallel along the second direction, each on which the light emitted from each light-emitting element in the plurality of rows is incident,
• third lens faces in a plurality of rows, in which a plurality of third lens faces are formed in an array along the first direction on the surface facing the photoelectric conversion device in a position on the second direction side and the optical transmission body side in relation to the first lens faces in the plurality of rows and the third lens faces are formed in a plurality of rows in parallel along the second direction, each emitting the monitor light of each light-emitting element in the plurality of rows that has been incident from an inner side of the first lens member towards the light-receiving elements in the plurality of rows,
• a first sloped surface that is disposed on the surface facing the photoelectric conversion device on a side opposite to the photoelectric conversion device, has a predetermined slope angle in relation to the surface facing the photoelectric conversion device to slope towards the optical transmission body side as the first sloped surface becomes farther from the surface, and totally reflects the light of each light-emitting element in the plurality of rows that has been incident on each of the first lens faces in the plurality of rows towards the optical transmission body side, and
• a second sloped surface that is disposed on the surface facing the photoelectric conversion device on a side opposite to the photoelectric conversion device and on the optical transmission body side in relation to the first sloped surface, has a predetermined slope angle in relation to the surface facing the photoelectric conversion device to slope towards a side opposite to the optical transmission body as the second sloped surface becomes farther from the surface, on which the light of each light-emitting element in the plurality of rows that has been totally reflected by the first slope surface is incident,
• the second lens member includes
• a third sloped surface that has a predetermined slope angle in relation to a surface facing the end face of the optical transmission body to slope towards a side opposite to the photoelectric conversion device as the third sloped surface becomes farther from the surface, faces the second sloped surface with a predetermined gap therebeween, and on which the light of each light-emitting element in the plurality of rows that has been incident on the second slope surface is incident, and
• second lens faces in a plurality of rows, in which a plurality of second lens faces are formed in an array along the first direction on the surface facing the end face of the optical transmission body and the second lens faces are formed in a plurality of rows in parallel along the third direction, each emitting the light of each light-emitting element in the plurality of rows that has been incident on the third slope surface towards the end face of the optical transmission body;
• an area between the second sloped surface and the third sloped surface is filled by a filler material of which a refractive index difference with the first lens member and the second lens member is a predetermined value or less;
• and
• a reflection/transmission layer is formed on the second sloped surface or the third sloped surface, the reflection/transmission layer reflecting the light of each light-emitting element in the plurality of rows that has been incident on the second sloped surface towards a side of the third lens faces in the plurality of rows as the monitor light of each light-emitting element in the plurality of rows at a predetermined reflectance, and transmitting the light of each light-emitting element in the plurality of rows towards the third sloped surface side at a predetermined transmittance.