US 2019/0154738 A1Published application

Sensor device having an integrated beam splitter

AssigneeABB Power Grids Switzerland AG

InventorsKlaus Bohnert, Andreas Frank, Yang Lin, Xun Gu, Georg Müeller

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Abstract

The optical interferometric sensor device comprises an integrated beam splitter having a first facet and a second facet with optical ports arranged therein. On the beam splitter, the beam splitting junctions as well as the optoelectronics-side ports and the sensing-side port are arranged with a mutual displacement along the direction of the first facet. This displacement reduces undesired interference effects caused by stray light. Also, a quarter-wave retarder is provided in a recess of the beam splitter with layers of soft adhesive adjacent to it in order to reduce stress.

Claims22

Dependent claims

An optical sensor device comprising:

a light source,
a first fiber, wherein light from said light source is coupled into said first fiber,
an integrated-optics beam splitter having an optoelectronics-side entry port, a first and a second optoelectronics-side exit port and a sensing-side port, wherein light entering said optoelectronics-side entry port is coupled at least partially into said sensing-side port and light entering said sensing-side port is split at least partially into said first and second optoelectronics-side exit ports, and wherein said first fiber is positioned to send light into said optoelectronics-side entry port,
a sensing element whose birefringence changes as a function of a measurand, wherein light from said sensing-side port is coupled into said sensing element, is reflected and is coupled back into said sensing-side port,
at least a second fiber and a third fiber, wherein light from said first and said second optoelectronics-side exit ports is fed into said second and third fibers, respectively,
light detectors for measuring light exiting from said second and third fibers,
wherein said beam splitter comprises
a) a plurality of waveguide sections and splitting junctions, and
b) a first and a second facet on opposite sides of said integrated-optics beam splitter, wherein said optoelectronics-side entry port and said optoelectronics-side exit ports are arranged at said first facet and said sensing-side port is arranged at said second facet,
wherein, in a direction Y parallel to said first facet, said sensing-side port is offset, by a non-zero minimum port-port-offset, in respect to said optoelectronics-side entry port and said first and second optoelectronics-side exit ports,
wherein in said direction Y, said sensing-side port is offset, by a non-zero minimum junction-port-offset, in respect to any junction that the light from said optoelectronics-side entry port passes on its way to said sensing-side port.

8 more elements

Dependencies are inferred from the claim text.

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Abstract

An optical sensor device comprising:

a light source,
a first fiber, wherein light from said light source is coupled into said first fiber,
an integrated-optics beam splitter having an optoelectronics-side entry port, a first and a second optoelectronics-side exit port and a sensing-side port, wherein light entering said optoelectronics-side entry port is coupled at least partially into said sensing-side port and light entering said sensing-side port is split at least partially into said first and second optoelectronics-side exit ports, and wherein said first fiber is positioned to send light into said optoelectronics-side entry port,
a sensing element whose birefringence changes as a function of a measurand, wherein light from said sensing-side port is coupled into said sensing element, is reflected and is coupled back into said sensing-side port,
at least a second fiber and a third fiber, wherein light from said first and said second optoelectronics-side exit ports is fed into said second and third fibers, respectively,
light detectors for measuring light exiting from said second and third fibers,
wherein said beam splitter comprises
a) a plurality of waveguide sections and splitting junctions, and
b) a first and a second facet on opposite sides of said integrated-optics beam splitter, wherein said optoelectronics-side entry port and said optoelectronics-side exit ports are arranged at said first facet and said sensing-side port is arranged at said second facet,
wherein, in a direction Y parallel to said first facet, said sensing-side port is offset, by a non-zero minimum port-port-offset, in respect to said optoelectronics-side entry port and said first and second optoelectronics-side exit ports,
wherein in said direction Y, said sensing-side port is offset, by a non-zero minimum junction-port-offset, in respect to any junction that the light from said optoelectronics-side entry port passes on its way to said sensing-side port.

8 more elements