Collimators are required to generate a parallel beam of light out of the naturally diverging light emission from an optical fiber. Most fiber optic collimators available are designed for a low NA and thin fibers. High NA fibers such as Polymer Optical Fibers (POF) and Hard Polymer cladding fibers with an NA above 0.38 cannot be collimated efficiently by of most these standard products, without a great reduction of output power. Prizmatix Collimator is designed to work with High NA fibers (up to 0.53) therefore provides efficient solution to this problem.
Output of free space POF fiber NA=0.5 (Left) and Collimator ourput with same fiber (Right)
Features
Optimal performance using Aspheric Lenses
High NA suited for High NA Polymer Optical Fibers (POF)
Reciprocal SMA, FC or ST fiber connection
Compact
Applications
Spot illumination
Component test and inspection
Can be used in reverse direction as a free-space to fiber coupler
Specifications
Lens NA:
0.53 suites for most high NA fibers
Fiber Connector:
SMA or FC
Dimensions:
Diameter:
0.70" (17.8mm)
Length:
1.11" (28.2mm)
Material:
Black anodized aluminum
Why is a collimator required?
Light emits from multimode fibers as a wide
cone of light. The opening angle θmax is dictated
by the internal total reflection in the fiber, and is
usually represented as the Numerical Aperture
(NA) of the fiber.
The general relation in air is:
NA= sin( θmax )
The following table compares the full emission
angle (2 θmax ) of common NA fibers:
Typical Fiber Type
Fiber Example
NA
Full Emission Cone
[Rad]
[Deg]
SILICA Optical Fiber
Polymicro Tech. Deep UV fiber FDA600660760
0.22
0.44
25.4
Hard Polymer Clad Multimode Fiber
Thorlabs BFL37-1000
0.37
0.76
43.4
Hard Polymer Clad Multimode Fiber
Thorlabs APCH1500
0.37
0.80
45.9
Hard Polymer Clad Multimode Fiber
Thorlabs BFH48-600
0.48
1.00
57.4
Polymer Optical Fiber (POF)
Mitsubishi Super ESKA SH4001
0.5
1.05
60.0
Liquid Light Guide
EXFO
0.6
1.29
73.7
Collimator Performance
Multimode high NA fibers are too large to be considered as a point source. Hence, the beam leaving
the collimator will not be perfectly collinear with the main axis, but slightly expanding. Roughly, beam divergence
angle after the collimator changes with the diameter of the fiber. Smaller fibers will yield small
divergence angle, whereas large core fibers will generate a larger divergence angle.
The following table indicates the pivot angle of the emission cone of Prizmatix Collimator for
High NA fibers:
UHP-Microscope-LED-405
