Fiber Optic Mating Sleeves and Bulkhead Adapters

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Wide-Key-Slot Mating Sleeve and Narrow Key Connector:
Recommended for Narrow Key FC/PC Connectors
Not Recommended for Narrow Key FC/APC Connectors

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Wide-Key-Slot Mating Sleeve and Wide Key Connector:
Recommended for All Wide Key Connectors

• 2.2 mm Wide-Key-Slot Mating Sleeves
• Designed for All FC/PC-Terminated Fibers
• <0.5 dB Insertion Loss* (Measured at 635 nm with FC/PC-Terminated SM600 Fibers)

Thorlabs' ADAFC2 Wide-Key-Slot Mating Sleeve has a square flange with through holes for custom assemblies or our blank connection panels. The ADAFC1 Wide-Key-Slot Mating Sleeve is designed for the D-hole of a standard rack-mount panel, such as our fiber connection panels. To view a drawing with the recommended mounting hole pattern, click the Docs icon () below. These mating sleeves are compatible with either our square-flange or D-hole L-brackets sold below. Our CAPF1 Metal Cap, sold separately, protects the exposed end of the mating sleeve. 

Flat FC/PC connectors are significantly less alignment sensitive than their angled FC/APC counterparts, making these wide-key-slot mating sleeves acceptable for narrow and wide key FC/PC connectors. Although these mating sleeves are mechanically compatible with narrow key FC/APC connectors, the wide-key slot makes it difficult to properly align the angled, narrow key FC/APC connector. For FC/APC applications, we therefore recommend the narrow-key-slot mating sleeves shown immediately below. All FC/PC and FC/APC patch cables manufactured by Thorlabs use narrow key connectors.

The ADAFC2 is also available premounted in an L-bracket.

*Please Note: When PM fiber is used, the insertion loss will increase to >1.0 dB. For mating PM fiber, we recommend using our PM fiber mating sleeves sold below.

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Narrow-Key-Slot Mating Sleeve and Narrow Key Connector:
Recommended for All Narrow Key Connectors

• 2.0 mm Narrow-Key-Slot Mating Sleeves
• Designed for FC/PC- or FC/APC-Terminated Fibers with 2.0 mm Narrow Keys
• <0.5 dB Insertion Loss* (Measured at 635 nm with FC-Terminated SM600 Fibers)

Thorlabs' ADAFC3 Narrow-Key-Slot Mating Sleeve has a square flange with through holes for custom assemblies or our blank connection panels. The ADAFC4 Narrow-Key-Slot Mating Sleeve is designed for the D-hole of a standard rack-mount panel, such as our fiber connection panels. To view a drawing with the recommended mounting hole pattern, click the Docs icon () below. These mating sleeves are compatible with either our square-flange or D-hole L-brackets sold below. Our CAPF1 Metal Cap, sold separately, protects the exposed end of the mating sleeve.

These narrow-key-slot mating sleeves allow for proper alignment of angled, narrow key FC/APC connectors. These sleeves are also mechanically compatible with narrow key FC/PC connectors, but the flat FC/PC connector is significantly less alignment sensitive, which makes the wide-key-slot mating sleeves shown immediately above an acceptable alternative. All FC/PC and FC/APC patch cables manufactured by Thorlabs use narrow key connectors.

The ADAFC3 is also available premounted in an L-bracket.

*Please Note: When PM fiber is used, the insertion loss will increase to >1.0 dB. For mating PM fiber, we recommend using our PM fiber mating sleeves sold below.

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Narrow-Precision-Key-Slot Mating Sleeve
and Narrow Key Connector:
Recommended for Narrow Key PM Fiber Connectors

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Wide-Precision-Key-Slot Mating Sleeve and Wide Key Connector:
Recommended for Wide Key PM Fiber Connectors
Not Recommended for Narrow Key PM Fiber Connectors

• Best Possible Matching of Polarization Axes in PM Fibers
• 2.0 mm Narrow Precision Key or 2.2 mm Wide Precision Key FC Connectors
• <1.0 dB Insertion Loss* (Measured at 635 nm with FC/PC- and FC/APC-Terminated PM630-HP Fibers)

Thorlabs' PM Fiber Mating Sleeves have housings made from a single piece of metal, as opposed to the typical two-piece design. This precision construction provides the best possible matching of polarization axes, making them ideal for FC/PC- or FC/APC-terminated PM fibers. To ensure the best performance, choose the mating sleeve that matches your key width. All FC/PC and FC/APC patch cables manufactured by Thorlabs use narrow key connectors. Our CAPF1 Metal Cap, sold separately, protects the exposed end of the mating sleeve.

Both mating sleeves have square flanges with through holes for compatibility for custom assemblies, our blank connection panels, or our square-flange L-brackets (sold below). To view a drawing with the recommended mounting hole pattern, click the Docs icon () below. We also offer both mating sleeves premounted in an L-bracket.

*Please Note: If using a non-PM fiber this insertion loss will typically be less than 0.5 dB, due to higher tolerancing than our non-PM mating sleeves sold above. 

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The SMA906-style connector's ferrule has a step, which requires a ceramic alignment sleeve when mating it with an SMA905-style connector. 

• Designed for SMA-Terminated Fibers
• <1.5 dB Insertion Loss (Typical Loss for a Pair of Ø200 µm Core Multimode Fibers)
• Sold Individually or in Packs of 10
• Vacuum-Compatible SMA to SMA Mating Sleeve Sold Below

These mating sleeves can be purchased individually or in packs of ten (Item # ADASMA-10) at a significant savings over the individual price. Each 10-pack includes ten mating sleeves, ten washers, ten nuts, ten alignment sleeves, and twenty dust caps to protect the exposed ends of the mating sleeves. The ADASMA is also available premounted in an L-bracket.

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The ADASMAV has a Ø0.063" (Ø1.6 mm) vent hole.

• Air-Spaced SMA to SMA Mating Sleeve for Ultra-High-Vacuum Applications
• Constructed from 304 Stainless Steel
• <1.5 dB Insertion Loss (Typical Loss for a Pair of Ø200 µm Core Multimode Fibers)
• Double-Bagged for Cleanroom Environments
• Compatible with Thorlabs' Vacuum-Compatible Multimode Fiber Optic Patch Cables

Thorlabs' ADASMAV Mating Sleeve is a vacuum-compatible version of the ADASMA SMA to SMA Mating Sleeve. Constructed using 304 stainless steel, this adapter is designed to be used within ultra-high vacuum systems (>10^-10 Torr) and features a Ø0.063" (Ø1.6 mm) vent hole in the side to allow trapped gases to escape (see image to the right). Unlike the standard version, the ADASMAV is only compatible with SMA905-style connectors. A 304 stainless steel washer and nut are included for custom mounting.

Vacuum Compatibility Information
Our vacuum-compatible adapter is chemically cleaned and prepared for vacuum applications before packaging. It is compatible directly out of the packaging with vacuum environments down to 10^-10 Torr. With additional cleaning and processing, it can be used at even lower pressures, only limited by the outgassing rate of the stainless steel (see the table above). The material properties of the stainless steel and the cleaning methods completed by the end user should be used to determine the appropriateness of these products and materials in a specific vacuum system. Please note that using caps or panels not rated for vacuum applications with the ADASMAV is not recommended.

We also offer other vacuum-compatible components which may be used in vacuum applications.

• Designed for ST/PC-Terminated Fibers
• 3/8"-24 UNF-2A Thread

Thorlabs' ADAST Mating Sleeve connects two ST/PC-terminated fiber optic cables. A washer and 3/8"-24 UNF-2A threaded nut are included for panel mounting. Our CAPT1 Metal Cap, sold separately, protects the exposed end of the mating sleeve.

The ADAST is also available premounted in an L-bracket.

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• Options for SC/PC-Terminated or LC/PC-Terminated Fibers

Thorlabs' ADASC1 Mating Sleeve connects two SC/PC-terminated fiber optic cables, while our ADALC1 Mating Sleeve connects two LC/PC-terminated fiber optic cables. Both sleeves incorporate two tabs that snap into place when inserted into a panel.

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ADAF1 Mating Sleeve Connecting Two Fiber Patch Cables

• Mate Any Fiber with Ø1.25 mm or Ø2.5 mm Ferrules
• Sold Individually or in Packs of 5

Thorlabs Ferrule Mating Sleeves are designed for use with any terminated fiber with a Ø2.5 mm ferrule, such as FC/PC, ST^®/PC, or SC/PC connectors, or with a Ø1.25 mm ferrule, such as LC/PC or MU/PC connectors. These split sleeves can be used to create a temporary, quick-release connection between two cables, as shown in the photo to the right. They are compatible with both ceramic and stainless steel ferrule connectors. They are also compatible with our optogenetics fiber optic cannulae, optogenetics patch cables, and empty ceramic ferrules.

Ceramic mating sleeves are available individually or in packages of five. Phosphor bronze mating sleeves are also available in packs of five. Ceramic can be easily cleaned in an autoclave, while phosphor bronze is slightly malleable and can be disconnected with less force as shown in the graphs below.

Item # Prefix	Compatible Ferrule Size	Insertion Loss	Length	Disconnect Force	Comparison Graphs	Material
ADAL1	1.25 mm Outer Diameter	<0.5 dB Typical (SM)a <1.0 dB Typical (MM)b	6.8 mm	14.5 N (3.3 lbf) Typicalc	Ceramic Ferrule Stainless Steel Ferrule	Ceramic (Zirconia)
ADAL4				7.1 N (1.6 lbf) Typicalc		Phosphor Bronze
ADAF1	2.5 mm Outer Diameter	<0.2 dB Typical (SM)d <1.0 dB Typical (MM)e	11.4 mm	15.8 N (3.5 lbf) Typicalf	Ceramic Ferrule Stainless Steel Ferrule	Ceramic (Zirconia)
ADAF4				14.4 N (3.2 lbf) Typicalf		Phosphor Bronze

• Tested using SM600 fiber at 635 nm with LC/PC connectors.
• Tested using Ø200 µm core, 0.39 NA multimode fiber with LC/PC connectors and an LED source at 617 nm.
• Tested using an LC/PC-type ferrule.
• Tested using SMF28 fiber at 1550 nm with FC/PC connectors.
• Tested using Ø200 µm core, 0.39 NA multimode fiber with FC/PC connectors and an LED source at 617 nm.
• Tested using an FC/PC-type ferrule.

• Mate an FC/PC-Terminated Fiber to an SMA-Terminated Fiber
  • 2.2 mm Wide-Key-Slot FC/PC Connector
  • SMA905-Style SMA Connector

Thorlabs' ADAFCSMA1 Mating Sleeve mates an FC/PC-terminated single mode (SM) or multimode (MM) fiber to an SMA-terminated MM fiber by bringing the tips into physical contact. Our CAPF1 and CAPN1 Metal Caps are designed to protect the FC and SMA ends of the mating sleeve, respectively. Please note that this mating sleeve is only compatible with SMA905-style connectors.

The typical insertion loss for mating an FC/PC-terminated SM fiber to an SMA-terminated MM fiber is less than 0.2 dB^a, while the typical insertion loss for mating an FC/PC-terminated MM fiber to an SMA-terminated MM fiber is less than 1.4 dB^b.

The ADAFCSMA1 is also available premounted in an L-bracket.

• Measured at 633 nm by mating an FC/PC-terminated SM fiber with a 0.12 NA to an SMA-terminated MM fiber with a Ø50 µm core.
• Measured at 633 nm by mating an FC/PC-terminated MM fiber to an SMA-terminated MM fiber; both fibers had Ø50 µm cores.

• Mate an FC/PC-Terminated Fiber to an ST/PC-Terminated Fiber
• <0.28 dB Insertion Loss (Typical Loss for a Pair of SM Fibers)

Thorlabs' ADAFCST1 Mating Sleeve mates an FC/PC-terminated single mode (SM) or multimode (MM) fiber to an ST/PC-terminated SM or MM fiber by bringing the tips into physical contact. It features a 2.2 mm wide-key-slot FC/PC connector and can be mounted in custom assemblies, our blank connection panels, or our square-flange L-brackets (sold below) for compatibility with 1/4"-20 (M6) mechanical assemblies. To view a drawing with the recommended mounting hole pattern, click the Docs icon
() below.

Our CAPF1 and CAPT1 Metal Caps, sold separately, are designed to protect the FC/PC and ST/PC ends of the mating sleeve, respectively.

• Mate an FC/PC-Terminated Fiber to an SC/PC-Terminated Fiber
• <0.11 dB Insertion Loss (Typical Loss for a Pair of SM Fibers)

Thorlabs' ADAFCSC1 Mating Sleeve mates an FC/PC-terminated single mode (SM) or multimode (MM) fiber to an SC/PC-terminated SM or MM fiber by bringing the tips into physical contact. It features a 2.2 mm wide-key-slot FC/PC connector and has a square flange with through holes compatible with our blank connection panels or square-flange L-brackets (sold below). To view a drawing with the recommended mounting hole pattern, click the Docs icon () below.

Our CAPF1 Metal Cap, sold separately, protects the exposed FC/PC end of the mating sleeve.

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HASMA Adapter Attached to an SMA-Terminated Fiber Patch Cable

• Ideal for OEM or Custom Applications
• 2.0 mm Narrow-Key-Slot FC/PC Bulkhead Adapter
• 2.2 mm Wide-Key-Slot FC/PC Bulkhead Adapter
• SMA905- or SMA906-Style Bulkhead Adapter
• Useful for Fiber-to-Free-Space Interfaces

Thorlabs Bulkhead Adapters each accept a fiber connector on one side and have threads that can be used to mount the adapter into an OEM or custom system. They are useful for applications that require light to be launched from a fiber into a free-space setup. The design aligns the front face of the connector ferrule with the rear surface of the adapter, as shown in the photo to the right, and allows the fiber to be placed in near-physical contact with any optics or instruments that are placed after the adapter.

For compatibility with FC/PC-terminated patch cables, we offer two bulkhead adapters: the HAFC2 with a 2.0 mm narrow-key slot and the HAFC with a 2.2 mm wide-key slot; for more details on narrow versus wide key connectors, please see our Intro to Fiber tutorial. Both adapters have 3.2 mm long, 3/8"-24 external mounting threads on the side opposite the FC/PC connector. To create 3/8"-24 taps in custom assemblies, Thorlabs offers the TAP3824 tap.

The HASMA adapter is 0.38" (9.65 mm) long, with a 1/4"-36 threaded barrel for use with SMA905- and SMA906-style terminated fiber optic patch cables. The threaded barrel can also be used with the lock nut for mounting within OEM or custom systems.

The uncommon mounting threads in these adapters will require the use of custom mounting solutions. We recommend engaging at least two threads for stability when using a custom mount, with thread locker (Loctite) as an option for permanent solutions. If tapping a hole is not an option, the adapters can also be epoxied in place.

If a custom or OEM solution is not desired, both adapters are also available mounted within unthreaded and SM-threaded disks for compatibility with our lens tube systems. Fiber and bulkhead caps are also available for preventing damage to the terminated fiber when it is not in use.

• Compatible with Either Square Flange or D-Hole FC Mating Sleeves
  (See Table to the Right)
• Single, Dual, and Quadruple Brackets Available
• Single and Dual Brackets Include One or Two CAPF1 Metal Caps

Thorlabs' Empty L-Brackets are provided for customers who purchase our unmounted FC mating sleeves separately. They allow the construction of L-bracket mating sleeves not offered from stock; for example, a narrow key connector and a wide key connector can be placed into one L-bracket.

These L-brackets contain one or two 1/4" (M6) through holes for easy mounting to a post, optical table, or breadboard. All L-brackets feature 4-40 tap(s) to secure a CAPF1 Metal Cap, available for purchase separately. Single versions include one CAPF1 Metal Cap, while dual versions include two.

The ADABS1, ADABS2, and ADABS3 include screws with 2-56 threading for attaching the square flange mating sleeves. Replacement screws (Item # SH2S019) are available in packs of 50.

Specifications
Refractive Index	402 nm	1.4995
	589.3 nm	1.4646
	980 nm	1.4462
	1550 nm	1.4378
Refractive Index Temperature Coefficient (25 °C to 60 °C)		-3.5 x 10-4 per °C
Refractive Index vs. Wavelength (Cauchy Fit)a		1.4338 + 10520 λ-2
Optical Absorption (450 - 750 nm)		<0.003% per µm
Apparent Viscosity (25 °C)		10,600 poises
Oil Separation (24 hrs at 100 °C)		0.2%
Evaporation (24 hrs at 100 °C)		1.0%
Specific Gravity (25 °C)		1.06
Thermal Coefficient of Expansion		0.0006 cc/cc/°C
Microscopic Particulate Contamination	10 - 34 µm	<300 Particles/cc
	≥35 µm	0 Particles/cc
Absorption Spectrum

• Wavelength λ in nm

Thorlabs' G608N3 Index Matching Gel is a crystal-clear optical coupling compound intended to reduce signal attenuation in wave guide assemblies at connections. The presence of air at the junction of two optical fibers causes significant signal refraction due to the large differential optical impedance that exists between air and the signal-carrying wave guides.

The optical coupling compound G608N3 has been formulated with the requisite optical properties of clarity, purity, and refractive index to minimize signal losses while allowing pliable mechanical connections between rigid parts. Unlike a rigid optical epoxy, this pliable gel is viscoelastic and can take up the differential thermal expansion of precision optical parts without inducing excessive stresses or delamination. Residue may be cleaned from fiber tips using methanol or isopropyl alcohol.

In many devices, these materials serve an additional function: they help seal out ambient dust or fluids from sensitive optical components. This gel is formulated to be ultraclean, non-yellowing, and unaffected by x-ray, ultraviolet or sunlight exposure. It has extremely low outgassing and volatility characteristics and is free from light-absorbing microscopic particulates. This optical product is a chemically stable, non-toxic, synthetic material with wide temperature serviceability and is suitable for designs with high reliability and long service life.

The table below gives data on the decrease in signal loss when using the gel. Each syringe comes with 3 cc of index matching gel. This index matching gel can also be used to refill our fiber-to-fiber splice kits.

• A 617 nm LED source was used to mate two multimode 0.22 NA, Ø50 µm core, Ø125 µm clad patch cords with and without index matching gel.
• A 780 nm fiber coupled laser source was used to mate two FC/PC-terminated 780HP fibers with and without index matching gel.