Triplet Fiber Collimation Packages
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Two TC12FC-633 Tripet Collimators Mounted in our POLARIS-K1
Kinematic Mirror Mounts Using AD12NT
Posts, and CF125
Clamping Forks. Triplet Fiber Collimation Packages can be Used for Collimator-to-Collimator Coupling with Working Distances from 50 mm to 2 m.
- Prealigned for 405, 543, 633, 780, 1064, 1310, or 1550 nm
- Available with 12 mm or 18 mm Effective Focal Lengths*
- Divergence ≤0.47° (See Tables Below for Details)
- Low Pointing Error
- FC/PC: 2 mrad (Max)
- FC/APC: 3 mrad (Max)
- Each Collimator Includes a Test Data Sheet
- Non-Magnetic Stainless Steel Housing
Thorlabs' Triplet Fiber Collimators use air-spaced triplet lenses that produce superior beam quality to aspheric lens collimators. The benefits of the low-aberration triplet design include an M2 term closer to 1 (Gaussian), less divergence, and less wavefront error. Detailed results of performance testing versus our fixed aspheric collimators is presented on the Performance tab. In order to take full advantage of the superior beam quality, our triplet collimators should be used with either single mode or polarization-maintaining fiber patch cables.
Our triplet fiber collimators are available from stock with seven different alignment wavelengths, effective focal lengths (EFL) of approximately 12 mm or 18 mm*, and either FC/PC or FC/APC connectors. The exact focal length at the specified wavelength for each collimator is given in the tables below. Each lens in the collimator has a broadband antireflection coating (see the Coatings tab) in order to minimize losses caused by surface reflections.
The packages use high-precision narrow-key receptacles with tightly toleranced ceramic sleeves that provide excellent pointing repeatability, allowing the user to remove and replace the fiber without needing to realign the system. The receptacles for the APC versions are angled so that light exiting the fiber enters the collimator perpendicular to the focal plane. The collimators with an EFL of about 12 mm are compatible with the Ø12 mm collimator mounting adapters, while the collimators with an EFL of about 18 mm are compatible with the Ø12 mm and Ø15 mm collimator mounting adapters.
For triplet collimators aligned to a wavelength other than what is available from stock, please contact Technical Support for additional information.
We also offer a line of aspheric fiber collimators, including our fixed collimators and our FiberPort adjustable collimation packages that are well suited for a wide range of wavelengths. For our complete line of collimation and coupling options, please see the Collimator Guide tab.
We recommend using triplet collimators with our AR-coated single mode fiber optic patch cables. These cables feature an antireflective coating on one fiber end for increased transmission and improved return loss at the fiber to free space interface. These cables are available with an AR-coated FC/PC or FC/APC connector. Alternatively, our large selection of standard fiber patch cables can also be used.
*See the tables below for the exact focal length at the specified wavelength for each Triplet Collimator.
Triplet Collimator Performance
Click for Details of Shaded Region
The graph above compares the pointing error of an aspheric lens collimator to that of a TC12 triplet collimator. Pointing error is graphed in X and Y components, each measured in microradians. Nineteen data points were taken with each collimator type and the beam's position was measured on a beam profiler.
Our triplet collimators use narrow-key fiber receptacles with tightly toleranced ceramic sleeves, leading to a pointing accuracy of an order of magnitude better than that of a similar aspheric lens collimator without a high-precision fiber receptacle. Features such as this make our triplet collimators an excellent choice for demanding applications.
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The graph above plots the beam quality, M2, of 68 TC12 triplet collimators and 68 aspheric collimators. The measured beam qualities have been binned into increments of 0.02. This data shows that beam quality when using a triplet collimator is typically closer to 1 than when using an aspheric collimator. It also shows that beam quality achieved with a triplet collimator is more consistent from unit to unit.
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This nearly Gaussian beam profile measured with our BC106-VIS beam profiler is of the beam created by collimating the output of a SM fiber-coupled HeNe laser using a TC12FC-633 Triplet Collimation Package.
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The graph above represents the wavefront error of a collimated beam using our TC12 triplet collimators. Each contour line represents 0.02 waves of wavefront error.
Another measure of a beam's quality is the flatness of the wavefront at an image plane conjugate to the fiber tip. Using our WFS150-5C wavefront sensor, we measured the wavefront of a 633 nm beam collimated with a triplet collimator. The result was less than λ/8 deviation from a flat wavefront.
Light exiting one triplet collimator can be fed back into a fiber through another triplet collimator, as seen in the photo on the Overview tab. The coupling efficiencies for pairs of triplet collimators sold on this page are plotted below as a function of the separation distance.
The divergence angle (in Degrees)
where D and f must be in the same units.
|θ ||Divergence Angle|
|D|| Mode-Field Diameter (MFD)|
|f||Focal Length of Collimator|
Theoretical Approximation of the Divergence Angle
The divergence angle listed in the specifications tables below is the measured beam divergence angle when using the fiber collimator at its design wavelength with the listed fiber. This divergence angle is easy to approximate theoretically using the formula shown below as long as the light emerging from the fiber has a Gaussian intensity profile. This works well for single mode fibers, but will underestimate the divergence angle for multimode fibers where the light emerging from the fiber has a non-Gaussian intensity profile.
Fiber Collimator Selection Guide
Click on the collimator type or photo to view more information about each type of collimator.
|Fixed FC, APC, or SMA Fiber Collimators||These fiber collimation packages are pre-aligned to collimate light from an FC/PC-, FC/APC-, or SMA-connectorized fiber. Each collimation package is factory aligned to provide diffraction-limited performance at one of six wavelengths: 405, 543, 633, 780, 1064, 1310, or 1550 nm. Although it is possible to use the collimator at detuned wavelengths, they will only perform optimally at the design wavelength due to chromatic aberration, which causes the effective focal length of the spheric lens to have a wavelength dependence.|
|Air-Spaced Doublet, Large Beam Collimators||For large beam diameters (Ø6.6 - Ø8.5 mm), Thorlabs offers FC/PC, SMA, and FC/APC air-spaced doublet collimators. These collimation packages are pre-aligned at the factory to collimate a laser beam propagating from the tip of an FC or SMA conectorized fiber and provide diffraction-limited performance at the design wavelength. |
|Adjustable Fiber Collimators||These snap-on collimators are designed to connect onto the end of an FC/PC or FC/APC connector and contain an AR-coated aspheric lens. The distance between the aspheric lens and the tip of the FC-terminated fiber can be adjusted to compensate for focal length changes or to recollimate the beam at the wavelength and distance of interest. |
|FiberPorts||These compact, ultra-stable FiberPort micropositioners provide an easy-to-use, stable platform for coupling light into and out of FC/PC, FC/APC, or SMA terminated optical fibers. It can be used with single mode, multimode, or PM fibers and can be mounted onto a post, stage, platform, or laser. The built-in aspheric or achromatic lens is available with three different AR coatings and has five degrees of alignment adjustment (3 translational and 2 pitch). The compact size and long-term alignment stability make the FiberPort an ideal solution for fiber coupling, collimation, or incorporation into OEM systems.|
|Triplet Collimators||Thorlabs' High Quality Triplet Fiber Collimation packages use air-spaced triplet lenses that offer superior beam quality performance when compared to aspheric lens collimators. The benefits of the low-aberration triplet design include an M2 term closer to 1 (Gaussian), less divergence, and less wavefront error. |
|Reflective Collimators||Thorlabs' metallic-coated Reflective Collimators are based on a 90° off-axis parabolic mirror. Mirrors, unlike lenses, have a focal length that remains constant over a broad wavelength range. Due to this intrinsic property, a parabolic mirror collimator does not need to be adjusted to accommodate various wavelengths of light, making them ideal for use with polychromatic light. Our reflective collimators are ideal for single-mode fiber.|
|Pigtailed Collimators||Our pigtailed collimators come with one meter of either single mode or multimode fiber, have the fiber and AR-coated aspheric lens rigidly potted inside the stainless steel housing, and are collimated at one of six wavelengths: 532, 830, 1030, 1064, 1310, or 1550 nm. Although it is possible to use the collimator at any wavelength within the coating range, the coupling loss will increase as the wavelength is detuned from the design wavelength. |
|GRIN Fiber Collimators||Thorlabs offers gradient index (GRIN) fiber collimators that are aligned for either 980, 1064, 1310, or 1550 nm and have either FC connectorized, APC connectorized, or unterminated fibers. Our GRIN collimators feature a Ø1.8 mm clear aperture, are AR-coated to ensure low back reflection into the fiber, and are coupled to standard single mode fibers.|
|GRIN Lenses||These graded-index (GRIN) lenses are AR coated for applications at 630, 830, 1060, 1300, or 1560 nm that require light to propagate through one fiber, then through a free-space optical system, and finally back into another fiber. They are also useful for coupling light from laser diodes into fibers, coupling the output of a fiber into a detector, or collimating laser light. Our GRIN lenses are designed to be used with our Pigtailed Glass Ferrules and GRIN/Ferrule sleeves.|