OZ Optics uses a patented tilt alignment technique to manufacture isolators with fiber pigtails. Light from an optical fiber is first collimated then transmitted through the isolator. If desired, a similar fiber pigtailed collimator can be mounted on the output end of the isolator for a fiber pigtailed isolator. The fibers can be standard single mode fibers or Large Mode Area (LMA) fibers. LMA fibers are used to reduce the optical power density in the fiber core and therefore allow guidance of larger input power levels while still achieving near-gaussian output beam quality. This patented tilt alignment technique allows OZ Optics to offer compact pigtailed devices. The isolators come with built-in windows to prevent dust contamination of internal isolator optics. These protection windows are easily removed and replaced by the user.