White Paper Non-Contact MPO Fiber Optic Connector Traditional MPO connectors require all fiber end faces to be in close physical contact at the same time. This is because of the fact that if there is an air gap, the light will be reflected between the end faces of the optical fiber (Fabry-Perot cavity) and seriously affects the stability of the signal. To ensure that all fiber end faces are in close contact at the same time, the fiber end face needs to protrude significantly from the surrounding surface, and a large working pressure is required on the optical fiber connector. ecause of the design, there are numerous problems with traditional MPO connectors. Figure 1. Non-contact MPO fiber connector (left) has an anti-reflective coating on the end face, compared to a conventional contact MPO connector (right) Non-contact MPO (NC-MPO) fiber connector has an optical fiber end face lower than the plastic ferrule surface, and an anti-reflection coating is on all the fiber end faces and the plastic ferrule surface (Fig. 1). When NC-MPO connectors are mated, there is a small air gap between all the fiber end faces. nti-reflection coating can prevent multiple reflection of light, while the lower fiber end face (Fig. 2) ensures that the mating fiber end face is not damaged. The working pressure on the NC-MPO connector is very small Figure 2. In a non-contact MPO fiber connector, the fiber end face is lower than the surrounding plastic ferrule surface (interferometer plot) The insertion loss test and return loss test reported in this paper are performed using test equipment model JGR-MS5.
Experiment 1: SM NC-MPO connector mated to SM NC-MPO connector side: 12-core SM NC-MPO connector (8 degree, coating); side: 12-core SM MPO physical contact connector (8 degree, no coating). NC-MPO connector under test: side: 12-core SM NC-MPO connector (8 degree, coating); -side: 12-core SM MPO physical contact connector (8 degree, no coating). Test method is shown below where the red part denotes anti-reflection coating on the ) Reference measurement: ) DUT measurement: DUT Due to the lack of reflection at the coated end face (see the next section), the insertion loss after mating needs to subtract.15 d from the test value. Pout = Pin (1-4%), Pout is the detection value of the photo detector, Pin is the actual insertion loss, loss of 4% is about.15d. Test procedure for connectors with coating t the reference measurement step, the end of the reference jumper is an -coated connector. s a result of the coating, the -side connector end face does not exhibit a 4% reflection loss. The photo detector receives power P out1 which is equal to the power P in1 at the output of the -side connector. P in1=pout1 t DUT test step, because the DUT's -side is a non-coated connector, the -side connector Pin1 Pout1
end face will have 4% reflection loss. The power received by the photo detector is P out2 = P in2 * (1-4%). DUT Pout2 Pin2 The final test result P out2 includes an extra 4% return loss in addition to the actual insertion loss P in2 of the DUT. This 4% (or.15d) needs to be subtracted from the measured insertion loss value. Test Result: Non-contact To Non-contact IL test Result For 12- core SM MPO(131nm) 6 5 4 3 2 1 52.8% 5 32.29% 31 1.42% 1 5.21%.% 5 6.% 5.% 4.% 3.% 2.% 1.%.%.% Non-contact To Non-contact IL test Result For 12- core SM MPO(155nm) 6 5 4 3 2 1 54.17% 3.21% 52 29 12.5% 12 3.13%.%.% 3 6.% 5.% 4.% 3.% 2.% 1.%.%
Experiment 2: SM NC-MPO connector mated to Special SM Uncoated MPO connector side: 12-core SM NC-MPO connector (8 degree, coating); -side: 12-core SM MPO physical contact connector (8 degree, no coating). MPO connector under test: -side: Special 12-core SM MPO connector (8 degree, no coating): fiber end is recessed from the ferrule surface, no coating. In other words, the fiber is recessed from the ferrule surface and will not cause damage to the coating on the opposing connector. -side: 12-core SM MPO physical contact connector (8 degree, no coating) Test method is shown below where the red part denotes anti-reflection coating on the ) Reference measurement ) DUT measurement DUT Pout = Pin (1-4%), Pout is the photo detector value, Pin is the actual insertion loss, again 4% loss is equivalent to.15d, which needs to be subtracted. Since the end of the DUT is a non-coated connector, a 4% loss is generated when the DUT -side is mated with the -side of the test jumper. Note this 4% loss is real. Therefore, the minimum loss in this case is.15 d. The loss distribution can be clearly shown in the following figure. Test Result:
Non-contact To Non-contact(uncoated) IL test Result For 12-core SM MPO(131nm) 25 2 15 1 5.% 8.7% 4 47.83% 22 34.78% 16 8.7% 4.17%.% 4 2 6.% 5.% 4.% 3.% 2.% 1.%.% 16 14 12 1 8 6 4 2 Non-contact To Non-contact(uncoated) IL test Result For 12-core SM MPO(155nm).% 27.66% 13 31.91% 15 25.53% 12 14.89% 7 35.% 3.% 25.% 2.% 15.% 1.% 2.8%.% 5.% 1.% 12-core SM NC-MPO Performance Summary
12-core Singlemode NC-MPO Statistical results Non-Contact 8 ( coated mated to coated) Non-Contact 8 ( coated mated to uncoated) 131nm 155nm 131nm 155nm Insertion Loss Return Loss Experiment 3: Multimode NC-MPO Connector mated to Multimode NC-MPO Connector: end face degree -side: 12-core MM NC-MPO connector ( degree, coating); -side: 12-core MM MPO physical contact connector ( degree, no coating). MPO connector under test: -side: 12-core MM NC-MPO connector ( degree, coating); -side: 12-core MM MPO physical contact connector ( degree, no coating). Test method is shown below where the red part denotes anti-reflection coating on the Mean value.6d.6d.25d.23d Standard deviation.4.4.5.6 97% distribution.16d.15d.35d.35d Repeatability <.1d <.1d <.1d <.1d Maximum value.2d.19d.39d.39d Minimum value.1d.1d.17d.15d Mean value 77.92d 8.12d 75.7d 75.44d Standard deviation 4.89d 3.28d 6.23 5.12 Maximum value 85.4d 83.6d 85.5d 83.7d Minimum value 69.9d 73.4d 65.1d 66.1d ) Reference measurement ) DUT measurement DUT Due to the lack of reflection at the coated end face, the insertion loss after mating needs to subtract.15 d from the test value. Test Result:
Non-contact To Non-contact IL test Result For 12-core MM MPO ( angle) 1 8 6 4 2 4.9% 89 16.67% 37 91 4.99% 1.35% 3.%.9% 2 45.% 4.% 35.% 3.% 25.% 2.% 15.% 1.% 5.%.%.%.% Experiment 4: Multimode NC-MPO Connector mated to Multimode NC-MPO Connector: end face 8 degree -side: 12-core MM NC-MPO connector (8 degree, coating); -side: 12-core MM MPO physical contact connector (8 degree, no coating) MPO connector under test: -side: 12-core MM NC-MPO connector (8 degree, coating) -side: 12-core MM MPO physical contact connector (8 degree, no coating) Test method is shown below where the red part denotes anti-reflection coating on the ) Reference measurement: ) DUT measurement: DUT
Due to the lack of reflection at the coated end face, the insertion loss after mating needs to subtract.15 d from the test value. Test Result: Non-contact To Non-contact IL test Result For 48- core MM MPO (8 angle) 14 12 1 8 6 4 2 65.% 117 27.22% 49 5.56% 1.67%.56%.% 1 3 1 7.% 6.% 5.% 4.% 3.% 2.% 1.%.% 12-core Multimode NC-MPO Performance Summary 12-core Multimode NC-MPO Statistical results From the test results, it can be seen that 12-core MM 8 angle NC-MPO has better performance than angle NC-MPO. Experiment 5: 48-core multimode NC-MPO Connector mated to 48-core multimode NC-MPO end face degree Insertion Loss Return Loss side: 48-core MM NC-MPO connector ( degree, coating); -side: 2 groups of 24-core MM MPO physical contact connector ( degree, no coating). MPO connector under test: Non-Contact ( coated mated to coated) side: 48-core MM NC-MPO connector ( degree, coating); Non-Contact 8 ( coated mated to coated) Wavelength: 85nm Mean value.5d.4d Standard deviation.4.4 97% distribution.15d.15d Repeatability <.1d <.1d Maximum value.28d.22d Minimum value.1d.1d Mean value 18.68d Standard deviation 2.3 Returned signal too small Maximum value 25.4d to detect. Minimum value 16.9d -side: 2 groups of 24-core MM MPO physical contact connector ( degree, no coating).
Test method is shown below where the red part denotes anti-reflection coating on the ) Reference measurement Dector ) DUT measurement DUT Dector Due to the lack of reflection at the coated end face, the insertion loss after mating needs to subtract.15 d from the test value. Test Result: Non-contact To Non-contact IL test Result For 48-core MM MPO ( angle) 14 12 1 8 6 4 2 7.2% 38 22.16% 24.24% 19.89% 117 128 15 13.64% 72 45 8.52% 2.84% 1.14%.38%.% 15 6 2 3.% 25.% 2.% 15.% 1.% 5.%.%
Experiment 6: 48-core Multimode NC-MPO connector mated to 48-core Multimode NC-MPO end face 8 degree -side: 48-core MM NC-MPO connector (8 degree, coating); -side: 2 groups of 24-core MM MPO physical contact connector ( degree, no coating). MPO connector under test: -side: 48-core MM NC-MPO connector (8 degree, coating); -side: 2 groups of 24-core MM MPO physical contact connector ( degree, no coating). Test method is shown below where the red part denotes anti-reflection coating on the ) Reference measurement ) DUT measurement Dector DUT Due to the lack of reflection at the coated end face, the insertion loss after mating needs to subtract.15 d from the test value.
Test Result: Non-contact To Non-contact IL test Result For 48-core MM MPO (8 angle) 3 25 2 15 1 5 15.73% 14 28.9% 26.97% 15.73% 1.11% 25 24 14 9 3.37%.% 3 3.% 25.% 2.% 15.% 1.% 5.%.% 48-core Multimode NC-MPO Performance Summary: 48-core Multimode NC-MPO Statistical results Insertion Loss Return Loss From the test results, it can be seen that 48-core MM 8 angle NC-MPO has better performance than angle NC-MPO. Non-Contact ( coated mated to coated) Non-Contact 8 ( coated mated to coated) Wavelength 85nm Mean value.16d.13d Standard deviation.79.65 97% distribution.31d.25d Repeatability <.1d <.1d Maximum value.42d.29d Minimum value.1d.2d Mean value 24.42d Standard deviation 1.793 Returned signal too Maximum value 27.1d small to detect. Minimum value 17.3d