摘要 |
An optical splitting member splits a light beam emitted by a light source into first light beam and second light beam. A coupling member couples the first light beam. An optical system converges the second light beam on a light receiving unit. A holding member holds the light source, the optical splitting member, the coupling member, and the optical system. A supporting member supports the holding member so that the holding member is rotatable about an optical axis of the light beam.
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