Abstract: An automated fiber optic rotary joint (FORJ) dynamically measures, using an angle encoder, twists in an optical fiber cable caused by movements of a mouse or other animal and automatically unwinds the optical fiber cable(s) by engaging a motor. To optimize its efficiency, the unwinding process is activated automatically only when the angle encoder reaches a predetermined threshold. In some embodiments, the optical fiber is unwound in increments of 360°. Various embodiments allow simultaneous transfer of optical signals through independent channels to and from multiple sites of a freely moving animal through a rotating interface and with minimal mechanical impact on the natural behavior of the animal. The design principle leads to a minimal variation of light transmission over rotation suitable for life science applications. A single channel FORJ device can be readily expanded to a two-, three- or more-channel device.

Abstract: An automated fiber optic rotary joint (FORJ) dynamically measures, using an angle encoder, twists in an optical fiber cable caused by movements of a mouse or other animal and automatically unwinds the optical fiber cable(s) by engaging a motor. To optimize its efficiency, the unwinding process is activated automatically only when the angle encoder reaches a predetermined threshold. In some embodiments, the optical fiber is unwound in increments of 360°. Various embodiments allow simultaneous transfer of optical signals through independent channels to and from multiple sites of a freely moving animal through a rotating interface and with minimal mechanical impact on the natural behavior of the animal. The design principle leads to a minimal variation of light transmission over rotation suitable for life science applications. A single channel FORJ device can be readily expanded to a two-, three- or more-channel device.

Abstract: An optical beam splitter is presented whereby more than one incoming substantially collimated beam of light is combined into a common light path and subsequently the combined beam is divided into multiple outgoing beams of light. Another configuration of the cascade beam splitter is whereby a single incoming beam of substantially collimated light is divided, in a cascade, into multiple outgoing beams of light of lower power. A cascade beam splitter can be used to divide a single incoming substantially collimated beam of light into multiple outgoing beams of light. The connectors at which light enters or exits the beam splitter device can be made to allow free-space substantially collimated light propagation and can include optical and optomechanical elements for the purpose of collimating the incoming beam(s) or aligning and focusing the outgoing beams onto the core of a single mode or a multimode fiber.

Abstract: An optical beam splitter is presented whereby more than one incoming substantially collimated beam of light is combined into a common light path and subsequently the combined beam is divided into multiple outgoing beams of light. Another configuration of the cascade beam splitter is whereby a single incoming beam of substantially collimated light is divided, in a cascade, into multiple outgoing beams of light of lower power. A cascade beam splitter can be used to divide a single incoming substantially collimated beam of light into multiple outgoing beams of light. The connectors at which light enters or exits the beam splitter device can be made to allow free-space substantially collimated light propagation and can include optical and optomechanical elements for the purpose of collimating the incoming beam(s) or aligning and focusing the outgoing beams onto the core of a single mode or a multimode fiber.