Thorlabs offers a variety of Fiber Optic Cannulae that are designed for in vivo optogenetics applications. Our cannulae are available with six different fiber types with fiber cores ranging from Ø105 µm to Ø400 µm and numerical apertures from 0.22 to 0.50. Fiber optic cannulae with a diffuser tip are also available. Ferrules are available in two sizes, Ø2.5 mm (FC) or Ø1.25 mm (LC); we also offer empty ceramic ferrules for cannula construction. Ferrules are made using stainless steel or ceramic (zirconia). Stainless steel ferrules are more easily scorable for adhesion to a specimen with dental cement, while ceramic ferrules provide a non-magnetic fiber delivery system. All cannulae are implantable using stereotaxic guidance and are compatible with our Optogenetics Patch Cables. In addition, a cannula can also be used as a small light source for microscopy, or whenever a small, compact fiber optic probe is needed.