FCM Collimators for High NA Fibers
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Collimators are required to transform naturally diverging light-emission from an optical fiber to a parallel beam of light. Most fiber-optic collimators available are designed for thin fibers with low NA. 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 most of these standard products without a great reduction in output power (see Appendix for a discussion why special high NA collimators are required). The Prizmatix FCM collimators are designed to work with High NA fibers and provide an efficient solution to this problem. Features • Optimal performance using high NA Aspheric Lenses • High NA suited for High NA Polymer Optical Fibers (POF) • Reciprocal SMA or FC or fiber connection • Compact Applications • Spot illumination • Component test and inspection • Can be used in reverse as a free-space to fiber coupler • FCM1-06 - 0.63 NA, output beam diameter 1 inch • FCM1-05 - 0.53 NA, output beam diameter 1 inch • FCM05-05 - 0.53 NA, output beam diameter 34 inch Fiber Connector: SMA or FC Material: Black anodized aluminum Collimated output of same fiber above Main Office Phone: +972-72-2500097 Fax: +972-72-2500096 European Sales Office Phone: +44 (0)77-9172-9592 Fax: +44 (0)20-7681-2977 North America Sales Office Phone: +1-(248)-436-8085 Fax: +1-(248)-281-5236 P.O.B. 244 Givat Shmuel 54101, Israel

The following table indicates the far field divergence angle of the Prizmatix Collimators for High NA fibers: Main Office Phone: +972-72-2500097 Fax: +972-72-2500096 European Sales Office Phone: +44 (0)77-9172-9592 Fax: +44 (0)20-7681-2977 North America Sales Office Phone: +1-(248)-436-8085 Fax: +1-(248)-281-5236 P.O.B. 244 Givat Shmuel 54101, Israel

Light emits from multimode fibers as a wide cone of light. The divergence angle dmax is dictated by the reflection between the fiber's core and cladding, according to their refractive index, and is usually represented as the fiber's Numerical Aperture (NA). The general relation in air is: NA = sin (^=) The following table compares the full emission angle (dmax) of common fibers: In collimator the fiber is placed at the focus of the collimator lens so the output rays will be parallel to the optical axis. Main Office Phone: +972-72-2500097 Fax: +972-72-2500096 North America Sales Office...

Prizmatix Standard collimators are designed for low NA fibers (like NA 0.22) therefore when high NA fiber is connected to such collimator the highly divergent rays will be lost (Fig. A3 (A)) resulting in significant power loses. Alternatively if high NA fiber will be connected to high NA collimator the collimator lens NA is matched to the NA of the fiber resulting in good power throughput (Fig.A3 (B)). Fig. A3: (A) High NA fiber connected to low NA Collimator Lens, (B) High NA fiber connected to high NA Collimator Lens The core diameter of the optical fiber will have significant effect on...

Prizmatix side, Rays passing through center of the lens (in red) will continue without refraction. The noninfinitesimal size of the object will cause the output rays to divergent at full angle . Multimode high NA fibers are in most cases too large to be considered a point source. Hence, the beam leaving the collimator will not be of constant diameter, but slightly expanding. Smaller fibers will yield a small divergence angle, whereas large core fibers will generate a larger divergence angle. In order to reduce the output beam divergence of the collimator, longer focal length lenses are...