Terminated Fiber Adapters

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Externally SM05-Threaded Fiber Adapters
Internally SM05-Threaded Fiber Adapters
Externally SM1-Threaded Fiber Adapters
Internally SM1-Threaded Fiber Adapters
Externally C-Mount-Threaded Fiber Adapters
Unthreaded Ø1/2" Fiber Adapters
Unthreaded Ø1" Fiber Adapters
Bulkhead Adapters
Externally SM1-Threaded Ferrule Adapters
Post-Mountable Ferrule Clamps

Threaded & Unthreaded Adapters
Thorlabs offers various types of fiber connector adapters, which allow the most common types of fiber connectors to be integrated with SM-threaded, C-Mount-threaded, or unthreaded components. Adapters for patch cables with FC/PC, FC/APC, SMA, ST^®/PC, SC/PC, or LC^®/PC connectors are available; we also offer externally SM1-threaded (1.035"-40) adapters for our patch cables with Ø1.25 mm or Ø2.5 mm ferrule ends. If the threading and connector combination you need is not shown below, please contact Tech Support. Our complete line of thread adapters can also be used to convert between threadings.

These adapters are commonly employed when building single mode or multimode fiber couplers and collimators or in other free-space coupling applications. They can also be utilized to provide light-tight coupling to our SM05- (0.535"-40) or SM1- (1.035"-40) threaded photodetectors and many of our power meter sensors. Our C-Mount-threaded fiber adapters are useful for connecting patch cables to our C-Mount cameras.

Bulkhead Adapters
Thorlabs' FC/PC and SMA Bulkhead Adapters contain one connector for the projection of light into free space. Their compact size, one-piece construction, and mounting threads make them ideal for OEM or custom applications. The design aligns the front face of the connector ferrule with the rear surface of the adapter. This allows the fiber to be placed in near-physical contact with any optics or instruments that are placed after the adapter.

Post-Mounting Adapters
Post-Mountable Ferrule Clamps are designed to hold fiber connectors securely and compactly in an experimental setup. Clamps are available for Ø1.25 mm, Ø2.5 mm, Ø3.2 mm, or Ø3.4 mm components, including FC/PC, FC/APC, SC/PC, ST/PC, and SMA connectors, as well as our GRIN fiber optic collimators. The flexure clamps include an 8-32 (M4) tapped hole for post mounting, and they use a 5/64" (2 mm) hex key to secure the ferrule.

Posted Comments:

robert (posted 2018-11-21 21:15:53.49)

These adapters are very useful thanks. We would also like a version of S120-FC for FC/APC cables, like the S1FCA but internal SM1 thread. We use S120-FC with your power meters, to measure power out of a fiber. We use a short SM1 tube so the beam can expand, to avoid saturating the power sensor. With an FC/APC on an S120-FC, the propagated light does not hit the sensor on-center, so not all the light is detected. Thanks for your consideration.

nbayconich (posted 2018-11-28 10:54:56.0)

Thank you for contacting Thorlabs. I will reach out to you to discuss our custom capabilities. As an alternative you can use the SM1FCA with the internally threaded SM1T1 coupler.

akn (posted 2018-07-01 23:32:15.017)

Regarding SM1FCA,kindly clarify asap: - Operating temperature range - Storage temperature range - Weight in gms

YLohia (posted 2018-07-03 10:01:44.0)

Hello, we do not specify any of these parameters other than the weight (approximately 10g). This is made of 303 Stainless Steel, so you can look up the relevant properties online to get a sense of operating/storage temperature.

leticia.tarruell (posted 2018-03-07 12:29:31.81)

Has Thorlabs any terminated adapter for SMA fiber connectors (such as S1SMA) with a 5º angle? That would be the equivalent of S1FCA (vs. SM1FC) but for angled SMA. Thanks!

llamb (posted 2018-03-14 11:02:19.0)

Hello, thank you for contacting Thorlabs. We do not currently have any angled SMA connectors, as SMA is also not a keyed connector. I will reach out to you directly to discuss alternatives and our custom capabilities.

jv (posted 2017-09-05 10:52:45.03)

Is there an S120 type adapter available with a solid, blank face? (Like a cap)

wskopalik (posted 2017-09-07 10:09:21.0)

This is a response from Wolfgang at Thorlabs. Thank you for your inquiry. There is an internally SM1-threaded end cap which has the item number SM1CP1. I think this is what you are looking for. I have also contacted you directly to provide further assistance.

pierrick.cheiney (posted 2017-06-21 14:11:04.07)

Hello, What is the tolerance on the tilt if I use a S1FCA connector in a SM1 lens mount (locked with a retaining ring). Thanks,

nbayconich (posted 2017-07-11 03:42:16.0)

Thank you for contacting Thorlabs. The mechanical angle of the fc/apc bulkhead has a standard tolerance of 4.05° ±30’(0.5°). The tilt of the z axis will depend on the components used together. For example If you were to mount S1FCA in something like LMR1 there is a perpendicularity spec of 0.002” over 1” between the SM1 bore and the mounting hole. Arctan(0.002)=0.115°, so then they would stack to ±0.62°. I will contact you directly about your application.

lucia.koubikova (posted 2017-06-08 16:53:15.537)

Hello, I am wondering, if there is a terminated fiber adapter that could be used together with the Vacuum-Compatible Multimode Fiber Optic Patch Cable in a setup inside a vacuum chamber. I would like to place the fiber in a Polaris mirror mount but I do not see any appropriate (vacuum and SMA905 compatible) adapter over here. Could you, please, give me some recommendation?

nbayconich (posted 2017-07-13 05:14:26.0)

Thank you for contacting Thorlabs. These terminated fiber adapters are not intended for use in a vacuum. The black anodization of the SM1SMA and SM05SMA adapters is not vacuum compatible. These SMA connectors are also made from 303 stainless steel which is not good for vacuum use. I will contact you directly about our custom capabilities.

richard (posted 2017-02-06 14:36:32.98)

I have a question about the S05FC adapter plate. Is this a 2-piece construction, i.e. is is essentially a HFCA Bulkhead Adapter (silver part) threaded into an adapter (black) with 0.5" OD? The reason for the question is that I have been using the SM05FC (external SM05 thread) which has this kind of 2-piece construction. I have been unable to achieve satisfactory centration. Even a custom centering ring referenced to the proud part of the HFCA won't work as there is less than 1 full thread proud of the black outer ring. I want to know if I use a S05FC, is the external 0.5" diameter going to be concentric to the fiber to within machining accuracy? (As it would be if parts are pressed rather than screwed together). I note that there does appear to be an adapter which looks like a 1-piece construction, the S05FCA. Unfortunately this seems only available for FC/APC.

tfrisch (posted 2017-02-14 03:14:19.0)

Hello, thank you for contacting Thorlabs. The two haves of S05FC are joined by 3/8"-24 threads. I will reach out to you directly regarding your needs for this application.

daaf.sandkuijl (posted 2015-07-30 07:25:30.967)

Using an FC/PC fiber adapter (such as PM20-FC) and an FC/PC connectorized fiber, what would be the typical repeatability from one adapter to the next and one fiber to the next in terms of centration of the fiber in the adapter (in microns), and in terms of tip/tilt error (in degrees)?

besembeson (posted 2015-09-24 09:06:39.0)

Response from Bweh at Thorlabs USA: We have not accessed such figures. However, this will largely depend on the tolerances of both the fiber and the adapter. The manufacturing based centration of the ferrule duct to the outer diameter is better than 20um. Then there is the deviation of the SM05 thread of the adapter that could be biggest. This is manufactured with an average tolerance of 2A (ISO tolerance system) and the sensor thread will be of class 2B but we have no figures on the centricity or tip/tilt error when these are screwed together.

scottie730318 (posted 2014-04-18 12:01:26.53)

Dear Sir: Is the "Externally SM1-Threaded Fiber Adapters" for SM1SMA only one size with Ø1" (25.4mm)for Precision XY Translation Mounts(LM1XY)? Is there SM1SMA with size for 25mm for LM1XY/M? Thanks Best Regards

jlow (posted 2014-04-18 03:10:04.0)

Response from Jeremy at Thorlabs: The only difference between the LM1XY and the LM1XY/M is the mounting hole on the bottom (#8-32 vs. M4). The central bore for LM1XY (/M) is SM1 threaded so the SM1SMA would be used in both the English and metric version.

mtandecki (posted 2014-01-24 19:08:14.113)

I would like to suggest an addition to the Thorlabs product line. We are using these FC/APC fiber adapters typically with the CP02 cage plates. However, we have two issues when doing so: 1. It is not that easy to have the key of the FC adapter align perfectly parallel with one of the sides of the cage plate, which is what we aim for when using PM fiber. 2. The light beam probably comes out perpendicular to the FC adapter, however, because of the thread between SM1FCA and CP02 the beam is not perpendicular to the cage plate anymore. In some cases it has been so bad that we had to rearrange an optics setup because subsequent mirrors wouldn't be able to compensate for this. Making a combined SM1FCA/CP02 part could easily get rid of these two issues during the production process. Same goes for the SM1FC adapters which we sometimes use for non-angled PM fiber. Other suggestions to remedy these two issues are also welcome.

alex.lambert (posted 2013-07-18 09:07:41.3)

How much angular misalignment, if any, would result from inserting a 2.0mm narrow key FC/APC connector into the SM1FCA adaptor's 2.2mm wide key? Will the output beam still be perpendicular to the adapter's face?

jlow (posted 2013-07-22 15:46:00.0)

Response from Jeremy at Thorlabs: The angular misalignment from the 0.2mm would be <1.8°. The output beam should still be quite perpendicular to the adapter's face since the angular misalignment is quite small.

tor (posted 2010-11-12 14:55:33.0)

A response from Tor at Thorlabs to johannes.trapp: Thank you for your interest in the SM05FC. The distance from the fiber tip to the adapters front surface is 0.84mm.

johannes.trapp (posted 2010-11-12 11:00:38.0)

whats the distance between the end facet of the inserted fiber and the surface of the adapter, i.e. how close can I get the fiber end (in the adapter) to an object if the adapter is placed directly onto that object? thanks

Greg (posted 2010-09-28 13:26:55.0)

A response from Greg at Thorlabs to lincoln.turner: Our SM1FCA is designed for a key width of 0.085" +0.0003/-0.0 (2.16 mm +0.008/-0.0), allowing it to accept either narrow or wide key widths. We will look into adding a narrow key version of these adapters to increase repeatability for customers like yourself. For the time being, we can offer wide key FC/APC connectors on custom patch cables, which will provide a more repeatable fit with our SM1FCA and SM05FCA.

lincoln.turner (posted 2010-09-28 19:50:30.0)

A great addition to your product line would be a version of the SM1FCA (and S05FCA) fiber adapters that are designed for PM fiber. Currently the key width on these plates is 2.3-2.4mm which does not match either the industry standard 2.1mm wide key or 2.0mm narrow key. Currently when you use your PM fiber patch leads (they have a narrow key) it is impossible to remove and reconnect the patch lead while maintaining a stable polarisation as the key can rotate by 1-2 degrees in the SM1FCA plate!

Laurie (posted 2009-04-13 08:14:34.0)

Response from Laurie at Thorlabs to tony: We currently do not offer an externally threaded connector adapter similar to what you have requested, although one option may be to use the S120-SC or the S120-LC with the SM1T2 Coupler, which will offer the external threads that you require. If this will not work for you, please let our technical support staff know, as we may be able to create a custom item for you with the required external threads.

tony (posted 2009-04-08 11:33:34.0)

Can you supply these externally threaded products with SC or LC connectors? I see that you are offering this with the new internally threaded adapters

TechnicalMarketing (posted 2008-02-07 15:58:23.0)

Thank you for pointing out that the product description was unclear on this point. We have updated the description.

acable (posted 2007-12-15 12:59:50.0)

It is not clear if the holes for the spanner wrench go through the body of these adapters, while you say "light tight coupling" the drawings are not clear on this point.

Externally SM05-Threaded Fiber Adapters

Externally SM05-Threaded (0.535"-40) Disks with FC/PC, FC/APC, SMA, ST/PC, SC/PC, or LC/PC Receptacle
Light-Tight Construction When Used with SM05 Lens Tubes
Compatible with Many of Our 16 mm Cage Plates

Note: The ST and SMA adapters have indents/dimples in the front surface to allow the adapter to be tightened with the SPW801 spanner wrench. Note that these indents do not go all the way through the disk. The FC receptacle is too large to include the tightening indents. Instead we recommend putting an FC connector into the receptacle of the adapter to aid in tightening.

Item #	SM05FC^a	SM05FCA^b	SM05SMA^c	SM05ST	SM05SC	SM05LC
Adapter Image (Click the Image to Enlarge)
Connector Type	FC/PC^d	FC/APC^d	SMA	ST/PC	SC/PC	LC/PC
Threading	External SM05 (0.535"-40)

The FC/PC bulkhead, without the SM05-threaded plate, is available separately below.
The SM05FCA is designed with a 4° mechanical angle to compensate for the refraction angle of the output beam.
The SMA bulkhead, without the SM05-threaded plate, is available separately below.
This connector uses a wide key (2.2 mm).

Internally SM05-Threaded Fiber Adapters

Internally SM05-Threaded Disks with FC/PC, FC/APC, SMA, ST/PC, SC/PC, or LC/PC Receptacle
Light-Tight Construction When Used with SM05 Lens Tubes
Compatible with Our Fiber Optic Power Meters

Item #	PM20-FC	PM20-APC^a	PM20-SMA	PM20-ST	PM20-SC	PM20-LC
Adapter Image (Click the Image to Enlarge)
Connector Type	FC/PC^b,c	FC/APC^c	SMA	ST/PC	SC/PC	LC/PC
Threading	Internal SM05 (0.535"-40)

The PM20-APC is designed with a 4° mechanical angle to compensate for the refraction angle of the output beam.
In certain angle-independent applications, this adapter may also be used with FC/APC connectors.
This connector uses a wide key (2.2 mm).

Externally SM1-Threaded Fiber Adapters

Externally SM1-Threaded (1.035"-40) Disks with FC/PC, FC/APC, SMA, ST/PC, SC/PC, or LC/PC Receptacle
Light-Tight When Used with SM1 Lens Tubes
Compatible with Many of Our 30 mm Cage Plates and Photodetectors

Each disk has four dimples, two in the front surface and two in the back surface, that allow it to be tightened from either side with the SPW909 or SPW801 spanner wrench. The dimples do not go all the way through the disk so that the adapters can be used in light-tight applications when paired with SM1 lens tubes. Once the adapter is at the desired position, use an SM1RR retaining ring to secure it in place.

For externally SM1-threaded Ø1.25 mm and Ø2.5 mm ferrule adapters, please see below.

Item #	SM1FC^a	SM1FCA^b	SM1SMA^c	SM1ST	SM1SC1	SM1LC
Adapter Image (Click the Image to Enlarge)
Connector Type	FC/PC^d	FC/APC^d	SMA	ST/PC	SC/PC	LC/PC
Threading	External SM1 (1.035"-40)

The FC/PC bulkhead, without the SM1-threaded plate, is available separately below.
The SM1FCA is designed with a 4° mechanical angle to compensate for the refraction angle of the output beam.
The SMA bulkhead, without the SM1-threaded plate, is available separately below.
This connector uses a wide key (2.2 mm).

Internally SM1-Threaded Fiber Adapters

Internally SM1-Threaded (1.035"-40) Disks with FC/PC, FC/APC, SMA, ST/PC, SC/PC, or LC/PC Receptacle
Light-Tight Construction When Used with SM1 Lens Tubes
Compatible with Many of Our Photodiode Power Sensors

Note: The APC adapter has two dimples in the front surface that allow it to be tightened with the SPW909 or SPW801 spanner wrench. The dimples do not go all the way through the disk so that the adapter can be used in light-tight applications when paired with SM1 lens tubes.

Item #	S120-FC^a	S120-APC^b	S120-SMA^c	S120-ST	S120-SC	S120-LC
Adapter Image (Click the Image to Enlarge)
Connector Type	FC/PC^d,e	FC/APC^e	SMA	ST/PC	SC/PC	LC/PC
Threading	Internal SM1 (1.035"-40)

The FC/PC bulkhead, without the SM1-threaded plate, is available separately below.
The S120-APC is designed with a 4° mechanical angle to compensate for the refraction angle of the output beam.
The SMA bulkhead, without the SM1-threaded plate, is available separately below.
In certain angle-independent applications, this adapter may also be used with FC/APC connectors.
This connector uses a wide key (2.2 mm).

Externally C-Mount-Threaded Fiber Adapters

Externally C-Mount (1.000"-32) Threaded Disks with FC/PC, FC/APC, or SMA Receptacle
Light-Tight Construction
Compatible with Our SPW909 and SPW801 Spanner Wrenches
Compatible with Our C-Mount Cameras

Note: Each adapter has dimples that allow it to be tightened with the SPW801 and SPW909 spanner wrenchs. Note that these indents do not go all the way through the disk. The APC and SMA adapters have four dimples, two on the front and two on the back, while the FC adapter has only two on the front.

Item #	CMTFC^a	CMTFCA^b	CMTSMA^c
Adapter Image (Click the Image to Enlarge)
Connector Type	FC/PC^d	FC/APC^d	SMA
Threading	External C-Mount (1.000"-32)

The FC/PC bulkhead, without the C-Mount-threaded plate, is available separately below.
The CMTFCA is designed with a 4° mechanical angle to compensate for the refraction angle of the output beam.
The SMA bulkhead, without the C-Mount-threaded plate, is available separately below.
This connector uses a wide key (2.2 mm).

Unthreaded Ø1/2" Fiber Adapters

Unthreaded Ø1/2" Disk with an FC/PC, FC/APC, or SMA Receptacle
Compatible with Optomechanics for Ø1/2" Optics
Light-Tight Construction

Item #	S05FC	S05FCA^a	S05SMA
Adapter Image (Click the Image to Enlarge)
Connector Type	FC/PC^b	FC/APC^b	SMA
Outer Diameter	1/2"
Disk Thickness	2.5 mm	1.5 mm	3.2 mm

The S05FCA is designed with a 4° mechanical angle to compensate for the refraction angle of the output beam.
This connector uses a wide key (2.2 mm).

Unthreaded Ø1" Fiber Adapters

Unthreaded Ø1" Disk with an FC/PC, FC/APC, or SMA Receptacle
Compatible with Optomechanics for Ø1" Optics
Light-Tight Construction

Note: Each adapter shown here has two small dimples for aligning the adapter with our SPW909 fixed spanner wrench or SPW801 adjustable spanner wrench. The dimples do not go all the way through the disk so that the adapters can be used in light-tight applications.

Item #	S1FC^a	S1FCA^b	S1SMA^c
Adapter Image (Click the Image to Enlarge)
Connector Type	FC/PC^d	FC/APC^d	SMA
Outer Diameter	1"
Disk Thickness	2.5 mm	2.5 mm	3.2 mm

The FC/PC bulkhead, without the unthreaded adapter plate, is available separately below.
The S1FCA is designed with a 4° mechanical angle to compensate for the refraction angle of the output beam.
The SMA bulkhead, without the unthreaded adapter plate, is available separately below.
This connector uses a wide key (2.2 mm).

Bulkhead Adapters

Zoom

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HASMA Adapter Attached to an SMA-Terminated Fiber Patch Cable

Ideal for OEM or Custom Applications
2.2 mm Wide-Key-Slot FC/PC Bulkhead Adapter
SMA905- or SMA906-Style Bulkhead Adapter
Project Light into Free Space

Thorlabs' Bulkhead Adapters contain one connector for the projection of light into free space, where the light can then be manipulated or used by other optical devices, such as lenses or detectors. Ideal for OEM or custom applications, 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. The lack of a second connector at this surface allows for the projection of light from the fiber into free space. It also allows the fiber to be placed in near-physical contact with any optics or instruments that are placed after the adapter.

The HAFC adapter has a 2.2 mm wide-key-slot FC/PC bulkhead for compatibility with our FC/PC-terminated fiber optic patch cables. Opposite the FC/PC connector is a 3/8"-24 external mounting thread used for mounting the bulkhead adapter into OEM or custom systems.

Our 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 SM-threaded disks (sold above) 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.

Externally SM1-Threaded Adapters for Fiber Patch Cables with Ferrule Ends

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An SM1LCM Adapter Shown in a KM100T SM1-Threaded Kinematic Mount with Ferrule-Terminated Patch Cable

Adapters with Flexure Clamp for Patch Cables with Ø1.25 mm (LC) or Ø2.5 mm (FC) Ferrule Ends
Externally SM1-Threaded (1.035"-40) Disks
Light-Tight When Used with Ø1" Lens Tubes
Compatible with Our 30 mm Cage Plates and Photodetectors

These Adapter Plates allow our patch cables with a Ø1.25 mm or Ø2.5 mm ferrule end to be mounted within SM1-threaded (1.035"-40) systems. A flexure clamp is used to secure the ferrule end of the patch cable; the SM1FCM clamps on a Ø2.5 mm bare ferrule while the SM1LCM clamps on the delrin sleeve of the Ø1.25 mm ferrule-terminated patch cables (see photo to the right).

The flexure clamp on each adapter is secured with a 3-48 cap screw, which is tightened using a 5/64" (2 mm) balldriver or hex key. Approximately 1.25 in-lbs (0.14 N·m) of torque is sufficient to secure the ferrule. When the ferrule is correctly positioned, the distance from the fiber end face to the adapter face is 0.01" (0.3 mm).

The disks are externally SM1-threaded (1.035"-40) and have four dimples, two in the front surface and two in the back surface, that allow it to be tightened from either side using an SPW909 or SPW801 Spanner Wrench. These dimples do not pass through the disk, ensuring the ferrule adapters are light-tight when used with SM1-threaded (1.035"-40) lens tubes. Once the adapter is in the desired position, use an SM1RR retaining ring to secure it in place.

Post-Mountable Ferrule Clamps

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FCM Clamp with Ø2.5 mm Ceramic Ferrule

Click to Enlarge
FCM32 Clamp with SMA Connector

Compact Flexure Clamps for Ø1.25 mm, Ø2.5 mm, Ø3.2 mm, or Ø3.4 mm Ferrules
8-32 (M4) Tapped Mounting Hole
Compatible with Ø1/2" Optical Posts

These Post-Mountable Ferrule Clamps allow fiber connectors to be mounted securely and compactly within an experimental setup. See the table below for compatible ferrule diameters and fiber connectors for each clamp. The fiber ferrule is clamped into the flexure mount using a 5/64" (2 mm) hex key. An 8-32 (M4) tapped hole on the bottom of the mount provides compatibility with our Ø1/2" optical posts.

Item #	Compatible Component Diameter	Compatible Components
FCM13(/M)	1.25 mm (0.05")	Ø1.25 mm Ferrules
FCM(/M)	2.5 mm (0.10")	Ø2.5 mm Ferrules, FC/PC, FC/APC, SC/PC, and ST/PC Connectors
FCM32(/M)	3.2 mm (0.13")	SMA Connectors
FCM34(/M)	3.4 mm (0.14")	GRIN Collimators

View All »Matching Part Numbers

Terminated Fiber Adapters

Externally SM05-Threaded Fiber Adapters

Internally SM05-Threaded Fiber Adapters

Externally SM1-Threaded Fiber Adapters

Internally SM1-Threaded Fiber Adapters

Externally C-Mount-Threaded Fiber Adapters

Unthreaded Ø1/2" Fiber Adapters

Unthreaded Ø1" Fiber Adapters

Bulkhead Adapters

Externally SM1-Threaded Adapters for Fiber Patch Cables with Ferrule Ends

Post-Mountable Ferrule Clamps