Fiber End Caps


  • End Caps with Diameters up to 8 mm
  • Available Uncoated or with 1064 nm VAR Coating
  • ≥Ø5 mm Caps Have Taper or Stem for Splicing
  • Ideal for High-Power Coupling or to Protect Photonic Crystal Fiber

FEC1

Ø1 mm End Cap

FEC15

Ø1.5 mm End Cap

FEC5-1064

Ø5 mm End Cap with Taper,
1064 nm VAR Coating

FEC8S-1064

Ø8 mm End Cap with Taper and Stem,
1064 nm VAR Coating

Application Idea

FEC8S-1064 End Cap Spliced onto a Ø400 µm Core Fiber
(Not Shown to Scale)

Related Items


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End Cap Splicer
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Image of an FEC5-1064 Ø5 mm end cap with tapered lead-in prepared for splicing in the GLZ4001EC CO2 End Cap Splicer.
Coreless End Cap
Click to Enlarge

Coupling Light into and Out of Standard Fiber vs. End-Capped Fiber
Common Specifications
Clear Aperturea >80%
Surface Quality 20-10 Scratch-Dig
Surface Flatnessa ≤λ/4 at 633 nm
Parellelism ≤5 arcsec
Substrate UV Fused Silica
  • For Both Ends of the Cap

Features

  • Ø1 mm to Ø8 mm UV Fused Silica Coreless End Caps
  • Tapered Lead-in Simplifies Splicing Fiber onto ≥Ø5 mm Caps
  • Versions with 1064 nm VAR-Coated Face to Reduce Back Reflections at the Air-to-Glass Interface
  • >80% Clear Aperture for Each End Face
  • ≤5 arcsec Parallelism Between End Faces
  • Protect Fiber End Face by Reducing Energy Density at Air-to-Glass Interface
  • Ideal for High-Power Fiber Lasers and Amplifiers, Biomedical Imaging, and Protecting Photonic Crystal Fiber
  • Splice onto Optical Fiber Using Our Vytran® CO2 End Cap Splicer

Thorlabs' UV fused silica end caps range in size from Ø1 mm to Ø8 mm. End caps with a 5 mm or 8 mm cap diameter have either a stem or tapered lead-in on one end to simplify splicing them onto a fiber. They are also available with a 1064 nm antireflection coating on the side opposite the taper to reduce back reflections. Specifications and dimensions are provided in the tables below.

Each end cap is coreless (no waveguide) to allow the incoming light to expand evenly in the homogeneous material. When spliced onto a fiber, the end cap reduces the intensity at the air-to-glass interface of the fiber face to prevent potential damage from high-power sources, such as Q-switched lasers or fiber amplifiers. End caps can also be used to seal off the air holes in photonic crystal fiber to prevent water from entering.

Application Note
These caps can be spliced onto optical fiber using our Vytran® CO2 End Cap Splicer. The GLZ4001EC Splicer is an advanced splicer that is designed for splicing numerous types of fiber directly onto a large-diameter end cap. Utilizing a tapered lead-in allows end caps up to Ø9.5 mm to be spliced, as shown in the image to the upper right. Without a lead-in the maximum end cap diameter is 5 mm.


Posted Comments:
Jacob Conner  (posted 2024-02-10 12:16:44.163)
Would be nice to have a selection of these with MM fiber pigtails already fused. 105/125, 50/125, 62.5/125 and larger as well as some HI-1060 and smf28 options.
cdolbashian  (posted 2024-02-13 01:49:34.0)
Thank you for reaching out to us with this product suggestion! This is indeed something I can suggest to our fiber-component division internally. We are always hungry for your thoughts, and appreciate suggestions like this.
Yazhou Wang  (posted 2024-02-06 19:22:52.32)
I would like to buy FEC5-1064 end cap, but I don't have equipment to splict it with my fiber (P-25/250DC-PM). Is it possible to help me splice FEC5-1064 end cap with my fiber? Best regards, Yazhou
jdelia  (posted 2024-02-15 11:15:48.0)
Thank you for contacting Thorlabs. I have reached out to you directly to discuss the feasibility of this request.
Garland Best  (posted 2022-12-07 12:53:46.45)
Can someone email me the diameter and length tolerances for your endcaps? gbest@ozoptics.com
cdolbashian  (posted 2022-12-28 10:25:31.0)
Thank you for reaching out to us with this inquiry Garland! For the component which you are interested: FEC2, the length tolerance: ±0.05mm while the diameter tolerance is: ±0.02mm.
Suwon Kim  (posted 2021-09-28 00:25:13.0)
To whom it may concern, I`m Suwon Kim from HBL Corporation in Korea. I want to know if the custom AR coating(915 nm) is possible on FEC8S. If it possible, please let me know about the price. Thank you.
azandani  (posted 2021-09-28 02:58:42.0)
Hello Suwon, thank you for contacting Thorlabs. Custom end-caps can be requested by emailing TechSales@Thorlabs.com. We will reach out to discuss the possibility of offering this directly.
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Fiber End Caps, Uncoated

Item # Dimensions (See Profile) Profile
(Click for Details)
Holder Compatible Splicing System
DCap LCap LStem DS/Ta θTaper GLZ4001EC GPX4000LZ
FEC1 1.0 mm 2.5 mm N/A N/A N/A ECH1V Yes! Yes!
FEC15 1.5 mm 3.8 mm ECH15V Yes! Yes!
FEC2 2.0 mm 5.0 mm ECH2V Yes! Yes!
FEC5 5.0 mm 12.5 mm N/A 1.8 mm 60° ECH5C Yes! Yes!
FEC8 8.0 mm 20.0 mm ECH8C Yes! -
FEC8S 8.0 mm 20.0 mm 4.0 mm 1.8 mm 60° ECH8C Yes! Yes!
  • Diameter of the Stem or the Smallest Part of the Taper
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
FEC1 Support Documentation
FEC1Fiber End Cap, Ø1.0 mm, Uncoated
$99.74
Today
FEC15 Support Documentation
FEC15Fiber End Cap, Ø1.5 mm, Uncoated
$99.74
Today
FEC2 Support Documentation
FEC2Customer Inspired! Fiber End Cap, Ø2.0 mm, Uncoated
$98.80
Today
FEC5 Support Documentation
FEC5Customer Inspired! Fiber End Cap, Ø5.0 mm, Tapered End, Uncoated
$82.33
Today
FEC8 Support Documentation
FEC8Customer Inspired! Fiber End Cap, Ø8.0 mm, Tapered End, Uncoated
$82.33
Today
FEC8S Support Documentation
FEC8SCustomer Inspired! Fiber End Cap, Ø8.0 mm, Tapered End with Stem, Uncoated
$86.73
Today
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Fiber End Caps, VAR Coated for 1064 nm

Item # Dimensions (See Profile) Profile
(Click for Details)
AR V Coatingb Holder Compatible Splicing System
DCap LCap LStem DS/Ta θTaper GLZ4001EC GPX4000LZ
FEC5-1064 5.0 mm 12.5 mm N/A 1.8 mm 60° R < 0.25%
at 1064 nm
(0° ± 5° AOI)
ECH5C Yes! Yes!
FEC8S-1064 8.0 mm 20.0 mm 4.0 mm 1.8 mm 60° ECH8C Yes! Yes!
  • Diameter of the Stem or the Smallest Part of the Taper
  • The antireflection coating is deposited on the side opposite the taper.
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
FEC5-1064 Support Documentation
FEC5-1064Fiber End Cap, Ø5.0 mm, Tapered End, 1064 nm VAR Coating
$88.63
Today
FEC8S-1064 Support Documentation
FEC8S-1064Fiber End Cap, Ø8.0 mm, Tapered End with Stem, 1064 nm VAR Coating
$93.15
Today