Bare Fiber Optic Terminator

Click for Details
The BFT1 magnetically secures the connector while a bare fiber is held in place using a spring-loaded clamp.

Features

• Use for the Temporary Termination of Single Mode or Multimode Optical Fiber
• Bare Fiber Terminator Holds Fiber and Connector without Epoxy
• Terminator Accepts Fiber Jacket Diameters from Ø125 µm to Ø1400 µm
• Compatible Only with the Fiber Connectors Sold Below
  
  • Single Mode Connectors with FC/PC, FC/APC, ST^®*/PC, or LC/PC Terminations
  • Multimode Connectors with SMA905, FC/PC, or ST/PC Terminations
• Rubber Grip Reduces Clamping Stress on Polarization-Maintaining Fiber, Minimizing Cross Coupling
• Fiber Stops for Aligning Fiber Tip within SMA905 and FC/PC Connectors Available
• Contact Tech Support for Custom Connectors with Different Bore Diameters

Thorlabs' BFT1 Bare Fiber Terminator and compatible connectors are used to temporarily terminate a bare fiber with common fiber connector styles. The reusable BFT1 is equipped with a magnet and alignment key to quickly attach and align the compatible connectors sold below; these connectors can be locked into place with a 0.05" (1.3 mm) hex key. Bare fiber, with jackets from Ø125 µm to Ø1400 µm, is secured on the other end of the BFT1 using a spring-loaded clamp with rubber grips to minimize stress on the fiber. The reduced clamping stress on the fiber makes the BFT1 ideal for use with polarization-maintaining fiber where environmental stresses can induce cross coupling. Reusable connectors for terminating single mode or multimode fibers are sold here and can be easily interchanged when used with the BFT1. SMA and FC/PC-terminated fiber stops, which are used to help align the stripped fiber end to the ferrule tip, can be purchased separately below.

The BFT1 only accepts the connectors sold on this page; these connectors feature a Ø0.22" (Ø5.5 mm) sleeve that is magnetically secured within the BFT1. The bare fiber adapter is reusable and can be easily cleaned out if the fiber breaks inside the connector by using WC100 clean out wires (sold separately below). We recommend attaching the desired connector and then feeding the stripped fiber through the connector. At this point, cleave the fiber using a fiber scribe and then pull the tip back so that it is flush with the ferrule end. For a demonstration of this, watch the animation to the right, and for detailed instructions, please see the Usage Tips tab.

As the BFT1 is designed for temporary termination applications, sub-optimal centration or alignment can occur due to fiber movement within the connector. Thorlabs offers both single mode and multimode connectors for permanent or highly stable termination applications. Our fiber patch cables are sold with connectors on both ends and a protective jacket.

*ST^® is a registered trademark of Lucent Technologies, Inc.

Click to Enlarge
Step 4: Align Fiber Tip with Ferrule End

Click to Enlarge
Step 3: Cleave Fiber

Click to Enlarge
Step 2: Feed Fiber Through the Connector

Click to Enlarge

Click to Enlarge

Step 1: Insert Connector and Rotate Until Magnetic Lock Engages

Click for Details
BFT-FSSMA Fiber Stop with the BFT1 and B10125A Connector

This tab contains step-by-step instructions on terminating a bare fiber using the BFT1 bare fiber terminator. The items in the images to the right are the BFT1, B10125A (Ø125 µm, multimode SMA905 connector), S90R fiber scribe, and BFT-FSSMA SMA905 fiber stop. These instructions are also engraved on the bottom surface of the BFT1. The animation to the right below illustrates the step-by-step usage of the BFT1.

Step 1: Insert the Ø0.22" (Ø5.5 mm) metal sleeve end of the connector into the BFT1. Rotate the connector within the hole of the BFT1 until the key and connector align; the connector should now be magnetically secured. For additional support, the connector can be locked in place by tightening the setscrew on the side of the BFT1 using a 0.05" (1.3 mm) hex key.

Step 2: Strip the fiber; for additional instructions on stripping and cleaning optical fiber, please see our connectorization guide.

Step 3: Use a manual cleaver (Item # CLV150) or fiber scribe (Item # S90R) to cleave the fiber, following the instructions provided with your cleaver or scribe. After this, use a finger to break the fiber at the cleave point. Alternatively, tape the cleaved end of the fiber to a table and then gently pull on the fiber from the back side of the BFT1 to break it at the cleaving point. Then, while pressing the spring-activated lever, slowly feed the fiber through the BFT1 from the clamp side until the fiber passes through both the BFT1 and the connector ferrule. Release the clamp to secure the fiber in position. Because debris can accumulate on the rubber grips of the clamp, which in some cases can cause fiber damage, we recommend clamping the fiber jacket rather than bare glass.

Step 4: Finally, while pressing the lever, gently pull the fiber back until the tip of the fiber is flush with the ferrule end. Release the lever in order to secure the fiber in position. Thorlabs does not recommend polishing the fiber while secured within the BFT1 as the fiber may be misaligned during the process.

If precise alignment is required, the BFT-FSSMA or BFT-FSFC fiber stops can aid with the fiber alignment in step 4. For this process, pull the fiber until the fiber tip is inside the ferrule. Attach the appropriate fiber stop to the other end of the connector (as shown in the image to the right) and then gently push the fiber until the tip contacts the ferrule inside the fiber stop. At this point, release the lever to lock the fiber in position and then remove the fiber stop. Please note that spring-loaded ferrules may compress slightly and that fiber tip alignment may depend on the ferrule compression.