Assisted 2x2 Pigtailed Fiber-optic Rotary Joint

The Assisted 2x2 Pigtailed Fiber-optic Rotary Joint is recommended for a high-stability optical connection. The motorized assistance allows its frictionless rotation. The sensor within the rotary joint detects torsion in a fiber-optic tether to a moving animal, turns the rotor accordingly, and lets the animal move without discomfort. These rotary joints have 2 optical channels with static side pigtailed with 1m long FC-connectorized optical fibers. Due to the space constriction with 2 FC connectors side by side, we have chosen to use two M3 receptacles on the rotating side. The patch cords have a 200 or 400 μm core, 0.37 or 0.57 NA optical fibers on both sides for maximum reliability (customization of fibers are possible on request). The optical channels follow separate paths and have low loss, minimum possible signal variations during rotation, and no crosstalk.

Inside the joints are optic fiber and high NA aspheric lenses to match high NA optical fibers of LED or Ce:YAG light sources used for fiber photometry. Aspheric lenses are optimized for 530 nm but perform reasonably well for other wavelengths.

The assisted pigtailed fiber-optic rotary joint is intended for fiber photometry experiments involving recordings at two different brain sites/regions of the smaller tethered behaving animals like mice.

Optical Fiber	see options
Input Fiber	2x 1 meter long, ARMO Black jacket, FC/PC
Output Fiber connector	2x M3 receptacle
Transmission	50 % (Typical)
Maximum Variation	< 1.5 % peak-to-peak
Design Wavelength	530 nm
Power Supply (torque assistance)	5 VDC, 2A - mini USB (included)
Start up Torque	< 200 µN·m