Terminated Fiber Adapters

Compatible with Lens Tubes, Optical Posts, Standard C-Mounts, or OEM Components
Options for FC/PC, FC/APC, SMA, ST^®/PC, SC/PC, and LC^®/PC Connectors
SM05- and SM1-Threaded Adapters and Post-Mountable Clamps for Ferrules

SM1FCV

Vacuum-Compatible
FC/PC Adapter,
2.2 mm Wide Key

SM05SMA

SMA Adapter

SM1FCA2

FC/APC Adapter,
2.0 mm Narrow Key

PM20-ST

ST^®/PC Adapter

SM1FCM

Ø2.5 mm Ferrule Adapter

FCM

Ø2.5 mm Ferrule Clamp

SM05SMA Fiber Adapter in an
SM05-Threaded
Cage Plate

S120-SC

SC/PC Adapter

SM05LCM

Ø1.25 mm Ferrule Adapter

Hide Overview

OVERVIEW

Quick Links
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 SM05-Threaded Ferrule Clamps
Externally SM1-Threaded Ferrule Clamps
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 narrow or wide key FC/PC, narrow or wide key FC/APC, SMA, ST^®*/PC, SC/PC, or LC^®/PC connectors are available; for more details on narrow versus wide key connectors, please see the Key Alignment tab. Vacuum-compatible wide key FC/PC and SMA conectors are available with external SM1 threading. Adapters without a locking connector mechanism are available for patch cables with a Ø2.5 mm ferrule end. We also offer flexure clamp adapters that allow our patch cables with a Ø1.25 mm or Ø2.5 mm ferrule end to be mounted within an SM05-threaded (0.535"-40) or SM1-threaded (1.035"-40) component. 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 free-space 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, SMA, and ST/PC Bulkhead Adapters contain one connector for applications that require the projection of light into free space (the ST/PC adapters are also available in packs of ten). Their compact size and mounting threads make them ideal for OEM or custom applications. Our FC/PC and SMA bulkhead adapters boast a one-piece construction that integrates easily with a custom application, while a compatible 3/8"-24 lock nut is sold separately for the ST/PC bulkhead adapter for OEM applications. The design of the adapters 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.

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

Hide Key Alignment

KEY ALIGNMENT

Click to Enlarge
Mating Between a Narrow-Key Mating Sleeve and Connector

Click to Enlarge
Mating Between a Wide-Key Mating Sleeve and Connector

FC/PC and FC/APC Patch Cable Key Alignment

FC/PC and FC/APC Patch Cables are equipped with either a 2.0 mm narrow or 2.2 mm wide alignment key that fits into a corresponding slot on a mated component. These keys and slots are essential to correctly align the cores of connected fiber patch cables and minimize the insertion loss of the connection.

As an example, Thorlabs designs and manufactures mating sleeves for FC/PC- and FC/APC-terminated patch cables to precise specifications that ensure good alignment when used correctly. To ensure the best alignment, the alignment key on the patch cable is inserted into the corresponding narrow or wide-key slot on the mating sleeve.

Wide-Key-Slot Mating Sleeves
2.2 mm wide-key-slot mating sleeves are compatible with both wide-key and narrow-key connectors. However, using a narrow-key connector in a wide-key slot will allow the connector to rotate slightly in the mating sleeve (as shown in the animation below and to the left). While this configuration is acceptable for patch cables with FC/PC connectors, for FC/APC applications, we recommend using narrow-key-slot mating sleeves to ensure optimum alignment.

Narrow-Key-Slot Mating Sleeves
2.0 mm narrow-key-slot mating sleeves allow for optimal alignment of angled, narrow-key FC/APC connectors, as shown in the animation below and to the right. Therefore, they are not compatible with connectors that have a 2.2 mm wide key. Please note that all FC/PC and FC/APC patch cables manufactured by Thorlabs use narrow key connectors.

Narrow-Key-Slot Mating Sleeve and Narrow Key Connector
Once a narrow key connector is inserted into a narrow-key-slot mating sleeve, the connector will not rotate. We therefore recommend these mating sleeves for FC/PC and FC/APC connectors with narrow keys.

Wide-Key-Slot Mating Sleeve and Narrow Key Connector
When a narrow key connector is inserted into a wide-key-slot mating sleeve, the connector has room to rotate. For narrow key FC/PC connectors, this is acceptable, but for narrow key FC/APC connectors, significant coupling losses will result.

Hide Insights

INSIGHTS

Insights into Optical Fiber

Scroll down to read about:

What factors affect the amount of light coupled into a single mode fiber?
Is the max acceptance angle constant across the core of a multimode fiber?

Click here for more insights into lab practices and equipment.

What factors affect the amount of light coupled into a single mode fiber?

Illustration of coupling conditions that will reduce amount of light coupled into a single mode fiber's guided mode.

Click to Enlarge

Figure 2 Conditions which can reduce coupling efficiency into single mode fibers include anything that reduces the similarity of the incident beam to the optical properties of the fiber's guided mode.

Illustration of coupling conditions that will provide optimal coupling efficiency

Click to Enlarge

Figure 1 For maximum coupling efficiency into single mode fibers, the light should be an on-axis Gaussian beam with its waist located at the fiber's end face, and the waist diameter should equal the MFD.

Adjusting the incident beam's angle, position, and intensity profile can improve the coupling efficiency of light into a single mode optical fiber. Assuming the fiber's end face is planar and perpendicular to the fiber's long axis, coupling efficiency is optimized for beams meeting the following criteria (Figure 1):

Gaussian intensity profile.
Normal incidence on the fiber's end face.
Beam waist in the plane of the end face.
Beam waist centered on the fiber's core.
Diameter of the beam waist equal to the mode field diameter (MFD) of the fiber.

Deviations from these ideal coupling conditions are illustrated in Figure 2.

These beam properties follow from wave optics analysis of a single mode fiber's guided mode (Kowalevicz).

The Light Source can Limit Coupling Efficiency
Lasers emitting only the lowest-order transverse mode provide beams with near-Gaussian profiles, which can be efficiently coupled into single mode fibers.

The coupling efficiency of light from multimode lasers or broadband light sources into the guided mode of a single mode fiber will be poor, even if the light is focused on the core region of the end face. Most of the light from these sources will leak out of the fiber.

The poor coupling efficiency is due to only a fraction of the light in these multimode sources matching the characteristics of the single mode fiber's guided mode. By spatially filtering the light from the source, the amount of light that may be coupled into the fiber's core can be estimated. At best, a single mode fiber will accept only the light in the Gaussian beam output by the filter.

The coupling efficiency of light from a multimode source into a fiber's core can be improved if a multimode fiber is used instead of a single mode fiber.

References
Kowalevicz A and Bucholtz F, "Beam Divergence from an SMF-28 Optical Fiber (NRL/MR/5650--06-8996)." Naval Research Laboratory, 2006.

Date of Last Edit: Jan. 17, 2020

Is the max acceptance angle constant across the core of a multimode fiber?

$Illustration of the refractive index profiles of step-index and graded-index multimode optical fibers$
Click to Enlarge

Figure 3: Step-index multimode fibers have an index of refraction (n ) that is constant across the core. Graded-index multimode fibers have an index that varies across the core. Typically the maximum index occurs at the center.

Acceptance angles of a graded-index multimode optical fiber

Click to Enlarge

Figure 5: Graded-index multimode fibers have acceptance angles that vary with radius ( ρ ), since the refractive index of the core varies with radius. The largest acceptance angles typically occur near the center, and the smallest, which approach 0°, occur near the boundary with the cladding (0 < ρ₁ < ρ₂). Air is assumed to surround the fiber.

Acceptance angles of a step-index multimode optical fiber

Click to Enlarge

Figure 4: Step-index multimode fibers accept light incident in the core at angles ≤|θ_max| with good coupling efficiency. The maximum acceptance angle is constant across the core's radius ( ρ ). Air is assumed to surround the fiber.

It depends on the type of fiber. A step-index multimode fiber provides the same maximum acceptance angle at every position across the fiber's core. Graded-index multimode fibers, in contrast, accept rays with the largest range of incident angles only at the core's center. The maximum acceptance angle decreases with distance from the center and approaches 0° near the interface with the cladding.

Step-Index Multimode Fiber
The core of a step-index multimode fiber has a flat-top index profile, which is illustrated on the left side of Figure 3. When light is coupled into the planar end face of the fiber, the maximum acceptance angle (θ_max) is the same at every location across the core (Figure 4). This is due to the constant value of refractive index across the core, since the acceptance angle depends strongly on the index of the cladding.

Regardless of whether rays are incident near the center or edge of the core, step-index multimode fibers will accept cones of rays spanning angles ±θ_max with respect to the fiber's axis.

Graded-Index Multimode Fibers
The core of a typical graded-index multimode fiber, shown on the right side of Figure 3, has a refractive index that is greatest at the center of the core and decreases with radial distance (ρ). The equation included below the diagram in Figure 5 shows that the radial dependence of the core's refractive index results in a radial dependence of the maximum acceptance angle and numerical aperture (NA). This equation also assumes a planar end face, normal to the fiber's axis that is surrounded by air.

Cones of rays with angular ranges limited by the core's refractive index profile are illustrated Figure 5. The cone of rays with the largest angular spread (±θ_max) occurs on the fiber's axis (ρ = 0). The angular spread decreases as the radial distance to the axis increases.

Step-Index or Graded Index?
A step-index multimode fiber has the potential to collect more light than a graded-index multimode fiber. This is due to the NA being constant across the step-index core, while the NA decreases with radial distance across the graded-index core.

However, the graded-index profile causes all of the guided modes to have similar propagation velocities, which reduces the modal dispersion of the light beam as it travels in the fiber.

For applications that rely on coupling as much light as possible into the multimode fiber and are less sensitive to modal dispersion, a step-index multimode fiber may be the better choice. If the reverse is true, a graded-index multimode fiber should be considered.

References
Keiser G, "Section 2.6." Optical Fiber Communications. McGraw-Hill, 1991.

Date of Last Edit: Jan. 2, 2019

Hide Externally SM05-Threaded Fiber Adapters

Externally SM05-Threaded Fiber Adapters

FC/PC (Narrow or Wide Key), FC/APC (Narrow or Wide Key), SMA, ST^®*/PC, SC/PC, or LC/PC Receptacles
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 receptacles are 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 #	SM05FC2^a	SM05FC^b	SM05FCA2^c	SM05FCA^c	SM05SMA^d	SM05ST^e	SM05SC	SM05LC
Adapter Image (Click the Image to Enlarge)
Connector Type	FC/PC, 2.0 mm Narrow Key	FC/PC, 2.2 mm Wide Key	FC/APC, 2.0 mm Narrow Key	FC/APC, 2.2 mm Wide Key	SMA	ST/PC	SC/PC^f	LC/PC
Threading	External SM05 (0.535"-40)

The narrow-key FC/PC bulkhead, without the SM05-threaded plate, is available separately below (Item # HAFC2). Note that its engraving is different.
The wide-key FC/PC bulkhead, without the SM05-threaded plate, is available separately below (Item # HAFC).
The SM05FCA2 and SM05FCA are 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 (Item # HASMA).
The ST/PC bulkhead, without the SM05-threaded plate, is available separately below (Item # HAST).
In certain angle-independent applications, this adapter may also be used with SC/APC connectors.

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

Part Number	Description	Price	Availability
SM05FC2	FC/PC Fiber Adapter Plate with External SM05 (0.535"-40) Threads, Narrow Key (2.0 mm)	$29.11	Today
SM05FC	FC/PC Fiber Adapter Plate with External SM05 (0.535"-40) Threads, Wide Key (2.2 mm)	$29.11	Today
SM05FCA2	FC/APC Fiber Adapter Plate with External SM05 (0.535"-40) Threads, Narrow Key (2.0 mm)	$38.91	Today
SM05FCA	FC/APC Fiber Adapter Plate with External SM05 (0.535"-40) Threads, Wide Key (2.2 mm)	$38.91	Today
SM05SMA	SMA Fiber Adapter Plate with External SM05 (0.535"-40) Threads	$33.26	Today
SM05ST	ST/PC Fiber Adapter Plate with External SM05 (0.535"-40) Threads	$33.26	Today
SM05SC	SC/PC Fiber Adapter Plate with External SM05 (0.535"-40) Threads	$65.58	Today
SM05LC	LC/PC Fiber Adapter Plate with External SM05 (0.535"-40) Threads	$65.58	Today

Hide Internally SM05-Threaded Fiber Connectors and Ferrule Adapter

Internally SM05-Threaded Fiber Connectors and Ferrule Adapter

FC/PC (Narrow or Wide Key), FC/APC (Narrow or Wide Key), SMA, ST^®*/PC, SC/PC, LC/PC, or Ø2.5 mm Ferrule Receptacles
Light-Tight Construction When Used with SM05 Lens Tubes
Compatible with Our Fiber Optic Power Meters

Note: The PM20-25 ferrule adapter is designed without a locking connector mechanism and accepts fiber patch cables with Ø2.5 mm ferrules for quick power meter measurements.

Item #	PM20-FC2^a	PM20-FC^b	PM20-APC2^c	PM20-APC^c	PM20-SMA^d	PM20-ST^e	PM20-SC	PM20-LC	PM20-25
Adapter Image (Click the Image to Enlarge)
Connector Type	FC/PC, 2.0 mm Narrow Key	FC/PC, 2.2 mm Wide Key	FC/APC, 2.0 mm Narrow Key	FC/APC, 2.2 mm Wide Key	SMA	ST/PC	SC/PC^f	LC/PC	Ø2.5 mm Ferrule
Threading	Internal SM05 (0.535"-40)

The narrow-key FC/PC bulkhead, without the SM05 internal threading, is available separately below (Item # HAFC2).
The wide-key FC/PC bulkhead, without the SM05 internal threading, is available separately below (Item # HAFC).
The PM20-APC2 and PM20-APC are designed with a 4° mechanical angle to compensate for the refraction angle of the output beam.
The SMA bulkhead, without the SM05 internal threading, is available separately below (Item # HASMA).
The ST/PC bulkhead, without the SM05 internal threading, is available separately below (Item # HAST).
In certain angle-independent applications, this adapter may also be used with SC/APC connectors.

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

Part Number	Description	Price	Availability
PM20-FC2	FC/PC Fiber Adapter Cap with Internal SM05 (0.535"-40) Threads, Narrow Key (2.0 mm)	$37.72	Today
PM20-FC	FC/PC Fiber Adapter Cap with Internal SM05 (0.535"-40) Threads, Wide Key (2.2 mm)	$37.72	Today
PM20-APC2	FC/APC Fiber Adapter Cap with Internal SM05 (0.535"-40) Threads, Narrow Key (2.0 mm)	$37.27	Today
PM20-APC	Customer Inspired! FC/APC Fiber Adapter Cap with Internal SM05 (0.535"-40) Threads, Wide Key (2.2 mm)	$37.27	Today
PM20-SMA	SMA Fiber Adapter Cap with Internal SM05 (0.535"-40) Threads	$37.72	Today
PM20-ST	ST/PC Fiber Adapter Cap with Internal SM05 (0.535"-40) Threads	$52.28	3 Weeks
PM20-SC	SC/PC Fiber Adapter Cap with Internal SM05 (0.535"-40) Threads	$52.28	Today
PM20-LC	Customer Inspired! LC/PC Fiber Adapter Cap with Internal SM05 (0.535"-40) Threads	$52.28	Today
PM20-25	Customer Inspired! Ø2.5 mm Ferrule Adapter Cap with Internal SM05 (0.535"-40) Threads	$37.72	Today

Hide Externally SM1-Threaded Fiber Adapters

Externally SM1-Threaded Fiber Adapters

FC/PC (Narrow or Wide Key), FC/APC (Narrow or Wide Key), SMA, ST^®*/PC, SC/PC, or LC/PC Receptacles
Vacuum-Compatible Versions of FC/PC Wide-Key and SMA Receptacles Available
Light-Tight When Used with SM1 Lens Tubes
Compatible with Many of Our 30 mm Cage Plates and Photodetectors

Note: 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 #	SM1FC2^a	SM1FC^b	SM1FCV	SM1FCA2^c	SM1FCA^c	SM1SMA^d	SM1SMAV	SM1ST^e	SM1SC1^f	SM1LC^f
Adapter Image (Click the Image to Enlarge)
Connector Type	FC/PC, 2.0 mm Narrow Key	FC/PC, 2.2 mm Wide Key	FC/PC, 2.2 mm Wide Key	FC/APC, 2.0 mm Narrow Key	FC/APC, 2.2 mm Wide Key	SMA	SMA	ST/PC	SC/PC^g	LC/PC
Vacuum Compatibility	-		>10^-10Torr	-			>10^-10 Torr	-
Threading	External SM1 (1.035"-40)

The narrow-key FC/PC bulkhead, without the SM1-threaded plate, is available separately below (Item # HAFC2). Note that its engraving is different.
The wide-key FC/PC bulkhead, without the SM1-threaded plate, is available separately below (Item # HAFC).
The SM1FCA2 and SM1FCA are 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 (Item # HASMA).
The ST/PC bulkhead, without the SM1-threaded plate, is available separately below (Item # HAST).
These adapters can only be threaded in place with the connector facing away from the internal threading.
In certain angle-independent applications, this adapter may also be used with SC/APC connectors.

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

Part Number	Description	Price	Availability
SM1FC2	FC/PC Fiber Adapter Plate with External SM1 (1.035"-40) Threads, Narrow Key (2.0 mm)	$34.45	Today
SM1FC	FC/PC Fiber Adapter Plate with External SM1 (1.035"-40) Threads, Wide Key (2.2 mm)	$34.45	Today
SM1FCV	Vacuum-Compatible FC/PC Fiber Adapter Plate with External SM1 (1.035"-40) Threads, Wide Key (2.2 mm)	$76.17	Today
SM1FCA2	Customer Inspired! FC/APC Fiber Adapter Plate with External SM1 (1.035"-40) Threads, Narrow Key (2.0 mm)	$36.54	Today
SM1FCA	FC/APC Fiber Adapter Plate with External SM1 (1.035"-40) Threads, Wide Key (2.2 mm)	$36.54	Today
SM1SMA	SMA Fiber Adapter Plate with External SM1 (1.035"-40) Threads	$33.61	Today
SM1SMAV	Vacuum-Compatible SMA Fiber Adapter Plate with External SM1 (1.035"-40) Threads	$60.14	Today
SM1ST	ST/PC Fiber Adapter Plate with External SM1 (1.035"-40) Threads	$32.04	Today
SM1SC1	SC/PC Fiber Adapter Plate with External SM1 (1.035"-40) Threads	$65.58	Today
SM1LC	LC/PC Fiber Adapter Plate with External SM1 (1.035"-40) Threads	$65.58	Today

Hide Internally SM1-Threaded Fiber Connectors and Ferrule Adapter

Internally SM1-Threaded Fiber Connectors and Ferrule Adapter

FC/PC (Narrow or Wide Key), FC/APC (Narrow or Wide Key), SMA, ST^®*/PC, SC/PC, LC/PC, or Ø2.5 mm Ferrule Receptacles
Light-Tight Construction When Used with SM1 Lens Tubes
Compatible with Many of Our Photodiode Power Sensors

Note: The APC adapters have two dimples in the front surface that allow them 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.

The S120-25 ferrule adapter is designed without a locking connector mechanism and accepts fiber patch cables with Ø2.5 mm ferrules for quick measurements with photodetectors or power sensors.

Item #	S120-FC2^a	S120-FC^b	S120-APC2^c	S120-APC^c	S120-SMA^d	S120-ST^e	S120-SC	S120-LC	S120-25
Adapter Image (Click the Image to Enlarge)
Fiber Connector Type	FC/PC, 2.0 mm Narrow Key	FC/PC, 2.2 mm Wide Key	FC/APC, 2.0 mm Narrow Key	FC/APC 2.2 mm Wide Key	SMA	ST/PC	SC/PC^f	LC/PC	Ø2.5 mm Ferrule
Threading	Internal SM1 (1.035"-40)

The narrow-key FC/PC bulkhead, without the SM1-threaded plate, is available separately below (Item # HAFC2). Note that its engraving is different.
The wide-key FC/PC bulkhead, without the SM1-threaded plate, is available separately below (Item # HAFC).
The S120-APC2 and S120-APC are 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 (Item # HASMA).
The ST/PC bulkhead, without the SM1-threaded plate, is available separately below (Item # HAST).
In certain angle-independent applications, this adapter may also be used with SC/APC connectors.

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

Part Number	Description	Price	Availability
S120-FC2	FC/PC Fiber Adapter Cap with Internal SM1 (1.035"-40) Threads, Narrow Key (2.0 mm)	$46.33	Today
S120-FC	FC/PC Fiber Adapter Cap with Internal SM1 (1.035"-40) Threads, Wide Key (2.2 mm)	$46.33	Today
S120-APC2	FC/APC Fiber Adapter Cap with Internal SM1 (1.035"-40) Threads, Narrow Key (2.0 mm)	$36.18	Today
S120-APC	Customer Inspired! FC/APC Fiber Adapter Cap with Internal SM1 (1.035"-40) Threads, Wide Key (2.2 mm)	$36.18	Today
S120-SMA	SMA Fiber Adapter Cap with Internal SM1 (1.035"-40) Threads	$46.33	3 Weeks
S120-ST	ST/PC Fiber Adapter Cap with Internal SM1 (1.035"-40) Threads	$46.33	Today
S120-SC	SC/PC Fiber Adapter Cap with Internal SM1 (1.035"-40) Threads	$58.21	Today
S120-LC	LC/PC Fiber Adapter Cap with Internal SM1 (1.035"-40) Threads	$58.21	Lead Time
S120-25	Customer Inspired! Ø2.5 mm Ferrule Adapter Cap with Internal SM1 (1.035"-40) Threads	$46.33	Today

Hide Externally C-Mount-Threaded Fiber Adapters

Externally C-Mount-Threaded Fiber Adapters

FC/PC (Narrow or Wide Key), FC/APC (Narrow or Wide Key), or SMA Receptacles
Light-Tight Construction
Compatible with Our SPW909 and SPW801 Spanner Wrenches
Compatible with Our C-Mount Cameras

Note: Each adapter has four dimples, two on the front and two on the back, that allow it to be tightened with the SPW801 and SPW909 spanner wrenches. Note that these indents do not go all the way through the disk so that the adapters can be used in light-tight applications when paired with C-mount extension tubes.

Item #	CMTFC2^a	CMTFC^b	CMTFCA2^c	CMTFCA^c	CMTSMA^d
Adapter Image (Click the Image to Enlarge)
Connector Type	FC/PC, 2.0 mm Narrow Key	FC/PC, 2.2 mm Wide Key	FC/APC, 2.0 mm Narrow Key	FC/APC, 2.2 mm Wide Key	SMA
Threading	External C-Mount (1.000"-32)

The narrow-key FC/PC bulkhead, without the C-Mount-threaded plate, is available separately below (Item # HAFC2). Note that its engraving is different.
The wide-key FC/PC bulkhead, without the C-Mount-threaded plate, is available separately below (Item # HAFC).
The CMTFCA2 and CMTFCA are 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 (Item # HASMA).

Part Number	Description	Price	Availability
CMTFC2	FC/PC Fiber Adapter Plate with C-Mount (1.00"-32) Threads, Narrow Key (2.0 mm)	$33.26	Today
CMTFC	FC/PC Fiber Adapter Plate with C-Mount (1.00"-32) Threads, Wide Key (2.2 mm)	$33.26	Today
CMTFCA2	FC/APC Fiber Adapter Plate with C-Mount (1.00"-32) Threads, Narrow Key (2.0 mm)	$51.09	Today
CMTFCA	FC/APC Fiber Adapter Plate with C-Mount (1.00"-32) Threads, Wide Key (2.2 mm)	$51.09	Today
CMTSMA	SMA Fiber Adapter Plate with C-Mount (1.00"-32) Threads	$33.26	Today

Hide Unthreaded Ø1/2" Fiber Adapters

Unthreaded Ø1/2" Fiber Adapters

FC/PC (Narrow or Wide Key), FC/APC (Narrow or Wide Key), or SMA Receptacles
Compatible with Optomechanics for Ø1/2" Optics
Light-Tight Construction

Item #	S05FC2^a	S05FC^b	S05FCA2^c	S05FCA^c	S05SMA^d
Adapter Image (Click the Image to Enlarge)
Connector Type	FC/PC, 2.0 mm Narrow Key	FC/PC, 2.2 mm Wide Key	FC/APC, 2.0 mm Narrow Key	FC/APC, 2.2 mm Wide Key	SMA
Outer Diameter	1/2"
Disk Thickness	2.5 mm		1.5 mm	1.5 mm	3.2 mm

The narrow-key FC/PC bulkhead, without the unthreaded adapter plate, is available separately below (Item # HAFC2). Note that its engraving is different.
The wide-key FC/PC bulkhead, without the unthreaded adapter plate, is available separately below (Item # HAFC). Note that its engraving is different.
The S05FCA and S05FCA2 are 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 (Item # HASMA).

Part Number	Description	Price	Availability
S05FC2	Ø1/2" FC/PC Fiber Adapter Plate Without Threads, Narrow Key (2.0 mm)	$33.26	Today
S05FC	Ø1/2" FC/PC Fiber Adapter Plate Without Threads, Wide Key (2.2 mm)	$33.26	Today
S05FCA2	Ø1/2" FC/APC Fiber Adapter Plate Without Threads, Narrow Key (2.0 mm)	$38.91	Today
S05FCA	Ø1/2" FC/APC Fiber Adapter Plate Without Threads, Wide Key (2.2 mm)	$38.91	Today
S05SMA	Ø1/2" SMA Fiber Adapter Plate Without Threads	$33.26	Today

Hide Unthreaded Ø1" Fiber Adapters

Unthreaded Ø1" Fiber Adapters

FC/PC (Narrow or Wide Key), FC/APC (Narrow or Wide Key), or SMA Receptacles
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 #	S1FC2^a	S1FC^b	S1FCA2^c	S1FCA^c	S1SMA^d
Adapter Image (Click the Image to Enlarge)
Connector Type	FC/PC, 2.0 mm Narrow Key	FC/PC, 2.2 mm Wide Key	FC/APC, 2.0 mm Narrow Key	FC/APC, 2.2 mm Wide Key	SMA
Outer Diameter	1"
Disk Thickness	2.5 mm				3.2 mm

The narrow-key FC/PC bulkhead, without the unthreaded adapter plate, is available separately below (Item # HAFC2). Note that its engraving is different.
The wide-key FC/PC bulkhead, without the unthreaded adapter plate, is available separately below (Item # HAFC).
The S1FCA2 and S1FCA are 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 (Item # HASMA).

Part Number	Description	Price	Availability
S1FC2	Ø1" FC/PC Fiber Adapter Plate Without Threads, Narrow Key (2.0 mm)	$34.45	Today
S1FC	Ø1" FC/PC Fiber Adapter Plate Without Threads, Wide Key (2.2 mm)	$34.45	Today
S1FCA2	Ø1" FC/APC Fiber Adapter Plate Without Threads, Narrow Key (2.0 mm)	$38.91	Today
S1FCA	Ø1" FC/APC Fiber Adapter Plate Without Threads, Wide Key (2.2 mm)	$38.91	Today
S1SMA	Ø1" SMA Fiber Adapter Plate Without Threads	$34.45	Today

Hide Bulkhead Adapters

Bulkhead Adapters

Click to Enlarge
LN3824 Lock Nut Secured to the HAST ST/PC Adapter

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
ST/PC Bulkhead Adapter and Compatible 3/8"-24 Lock Nut
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.

Click to Enlarge
HASMA Adapter Attached to an SMA-Terminated Fiber Patch Cable

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. 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.

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 HAST adapter is a 0.58" (14.8 mm) long adapter for use with ST/PC terminated fiber optic patch cables. It has 0.18" (4.6 mm) of external 3/8"-24 external threads. The LN3824 Lock Nut, which has internal 3/8"-24 threads, may be purchased separately for mounting within OEM or custom systems. Both the HAST adapter and LN3824 are also available in packs of ten.

The uncommon mounting threads in these adapters will require the use of custom mounting solutions. The HAFC2, HAFC, and HASMA adapters may directly screw into an adapter plate. In order to mount the HAST adapter, the LN3824 lock nut must first be threaded onto the adapter (see the photo above). Once the lock nut is secure, the assembly may be threaded onto an adapter plate with a thread depth of at least 0.10" (2.54 mm). Please note that the HAST adapter and LN3824 lock nut are machined so that the maximum amount of torque needed to secure them into the adapter plate should not exceed 121.6 oz-lbs (0.86 N•m).

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, the adapters are also available mounted within unthreaded and 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. For OEM inquiries, please contact techsales@thorlabs.com.

Part Number	Description	Price	Availability
HAFC2	FC/PC Bulkhead Adapter, Narrow Key (2.0 mm)	$20.68	Today
HAFC	FC/PC Bulkhead Adapter, Wide Key (2.2 mm)	$20.68	Today
HASMA	SMA Bulkhead Adapter with Lock Nut	$9.38	Today
HAST	ST/PC Bulkhead Adapter	$8.42	Today
HAST-P10	ST/PC Bulkhead Adapter, 10 Pack	$81.60	Today
LN3824	3/8"-24 Lock Nut	$3.57	Today
LN3824-P10	3/8"-24 Lock Nut, 10 Pack	$34.68	Today

Hide Externally SM05-Threaded Adapters for Fiber Patch Cables with Ferrule Ends

Externally SM05-Threaded Adapters for Fiber Patch Cables with Ferrule Ends

Click to Enlarge
An SM05LCM Adapter Shown in a KM05T SM05-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 SM05-Threaded (0.535"-40) Disks
Light-Tight When Used with Ø1/2" Lens Tube
Compatible with Our 16 mm Cage Plates

These Adapter Plates allow our patch cables with a Ø1.25 mm or Ø2.5 mm ferrule end to be mounted within SM05-threaded (0.535"-40) systems. A flexure clamp is used to secure the ferrule end of the patch cable; the SM05FCM clamps on a Ø2.5 mm bare ferrule while the SM105CM 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 2-56 cap screw, which is tightened using a 5/64" (2 mm) balldriver or hex key. Approximately 2.0 in-lbs (0.23 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 SM05-threaded (0.535"-40) and ensure that the ferrule adapters are light-tight when used with SM05-threaded (0.535"-40) lens tubes.

*Delrin^® is a registered trademark of DuPont Polymers, Inc.

Part Number	Description	Price	Availability
SM05LCM	Customer Inspired! Ø1.25 mm Ferrule Adapter Plate with External SM05 (0.535"-40) Threads	$33.15	Today
SM05FCM	Customer Inspired! Ø2.5 mm Ferrule Adapter Plate with External SM05 (0.535"-40) Threads	$33.15	Today

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

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

Click to Enlarge
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.

*Delrin^® is a registered trademark of DuPont Polymers, Inc.

Part Number	Description	Price	Availability
SM1LCM	Customer Inspired! Ø1.25 mm Ferrule Adapter Plate with External SM1 (1.035"-40) Threads	$36.54	Today
SM1FCM	Customer Inspired! Ø2.5 mm Ferrule Adapter Plate with External SM1 (1.035"-40) Threads	$36.54	Today

Hide Post-Mountable Ferrule Clamps

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^®a/PC Connectors
FCM32(/M)	3.2 mm (0.13")	SMA Connectors
FCM34(/M)	3.4 mm (0.14")	GRIN Collimators

ST is a registered trademark of Lucent Technologies, Inc.

Part Number	Description	Price	Availability
FCM13/M	Post-Mountable Ø1.25 mm Ferrule Clamp, M4 Tap	$26.37	Today
FCM/M	Post-Mountable Ø2.5 mm Ferrule Clamp, M4 Tap	$22.93	Today
FCM32/M	Post-Mountable Ø3.2 mm Ferrule Clamp, M4 Tap	$26.37	Today
FCM34/M	Post-Mountable Ø3.4 mm Clamp, M4 Tap	$26.37	Today
FCM13	Post-Mountable Ø1.25 mm Ferrule Clamp, 8-32 Tap	$26.37	Today
FCM	Post-Mountable Ø2.5 mm Ferrule Clamp, 8-32 Tap	$22.93	Today
FCM32	Post-Mountable Ø3.2 mm Ferrule Clamp, 8-32 Tap	$26.37	Today
FCM34	Post-Mountable Ø3.4 mm Clamp, 8-32 Tap	$26.37	Today