Features

• Achromatic Design for Nearly Gaussian Collimation
  Over the Mirror's Reflection Band
• UV-Enhanced Aluminum or Protected Silver Coating Offers High Reflection
• Great for Coupling Polychromatic Light into Multimode Fiber
• Ø11 mm or or Ø22 mm Aperture
• Non-Magnetic Stainless Steel Housing

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.

By using the UV-ehnanced aluminum-coated (250 nm to 450 nm) or protected silver-coated (450 nm - 20 µm) mirrors, these collimators offer excellent usability over their design wavelength ranges. Please see the Graphs Tab for more information. Common applications include systems that utilize multiple wavelengths that need to be collimated, collimation/coupling in the IR, and coupling polychromatic light into large core multimode fiber.

Note that light cannot be well collimated from a multimode fiber. However, if you are attempting to collimate light from multimode fiber, the Numerical Aperture (NA) of the fiber should be <0.36 (RC04), <0.167 (RC08), or <0.216 (RC12) to avoid the collimator housing from clipping light emitted from the fiber tip. As the core size of the fiber gets larger, the resulting minimum divergence angle will increase as well, thus yielding an output that cannot be well-collimated.

Beam Diameter
Reflective collimators create a collimated beam that is proportional to the NA of the fiber you are collimating out of. To approximate this, use the following equation:

Output Diameter = 2 x NA (Fiber) x EFL

Depending on how the NA of the fiber is specified, the above equation gives the 5% level or 1% level (not the 1/e² value).

Fiber Patch Cables for Reflective Collimators
We recommend using reflective collimators with our AR-coated single mode or multimode fiber optic patch cabless for both coupling and collimating applications. 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 (SM), FC/APC (SM), or SMA (MM) connector. Alternatively, our large selection of standard fiber patch cables can also be used.

^a FC/PC and FC/APC versions use wide key connectors.
^b Approximate, based on 0.13 NA fiber
^c Effective Focal Length
^d Parent Focal Length: Off-axis parabolic mirrors can be made individually or cut from an on-axis parent parabolic mirror. When an off-axis parabolic mirror is cut from a parent on-axis parabolic mirror, we have a parent focal length (PFL) spec that arises. The PFL is the EFL of the parent mirror. Note that the EFL specified in the table above is that of the off-axis parabolic mirror. See the drawing to the right for more information.

Fiber Collimator Selection Guide

Click on the collimator type or photo to view more information about each type of collimator.

Type		Description
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 or graded-index multimode 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.