High data rate few-mode transmission over graded-index single-mode fiber using 850 nm single-mode VCSEL.

A few-mode transmission system is proposed using 850 nm single-mode VCSEL based transceivers over graded-index single-mode fibers for high data rate data center applications. A graded-index single-mode fiber that supports two mode groups at 850 nm window with a high modal bandwidth of 48.3 GHz·km is realized for the first time. 25 Gb/s transmission experiments using a 850 nm single-mode VCSEL over such fiber demonstrate that the system can support a link distance up to 1.5 km. Additionally, link model analysis provides more insights on how fiber and single-mode VCSEL parameters impact the system performance.

Transmission of wireless signals using space division multiplexing in few mode fibers.

Evolution of next generation wireless networks brings challenges to efficiently transmit a large amount of data from a base station to a remote antenna unit. We investigate a space division multiplexing technique that employs few mode fibers (FMFs) to transmit 3 × 3 MIMO wireless signals, aiming to employ a common digital signal processing (DSP) unit to equalize both the fiber and wireless channel. We optimize system parameters and obtain above 28 dB and 23 dB signal-to-interference and noise ratio (SINR) for 3 meters wireless systems with 500 m and 2 km FMF, which correspond to the transmission capacity of 578 Mb/s and 468 Mb/s using a 20 MHz bandwidth, respectively. Moreover, we analyze that the nonlinear spectrum distortion due to the combined effect of nonlinearity in the directly modulated laser and the differential mode delay in multimode fibers and validate it by simulations.

Design of universal fiber with demonstration of full system reaches over 100G SR4, 40G sWDM, and 100G CWDM4 transceivers.

Universal fiber has an LP01 mode field diameter approximately matched to that of standard single mode fiber, while being a multimode fiber. We analyzed the dependence of the mode field diameter on the core diameter for different core delta values. Guided by the analysis, a universal fiber having a delta of 1.2% was fabricated, showing significantly reduced coupling loss of ~2.3 dB with conventional multimode fiber. We demonstrated that the fiber can transmit with full system reach in both single mode and VCSEL-based multimode transmissions, including 100G SR4, 40G sWDM, and 100G CWDM4 for the first time.

25 Gb/s transmission over 820 m of MMF using a multimode launch from an integrated silicon photonics transceiver.

A new high bandwidth bend-insensitive MMF optimized for 1310 nm is designed and characterized. 25 Gb/s transmission over a record 820 m length using a multimode launch from an integrated SiPh transceiver at 1310 nm through the new fiber is demonstrated with a power penalty of 3.4 dB at 10(-12) BER. Detailed characteristics of the fiber and transceiver are presented along with BER measurements.

300m transmission over multimode fiber at 25Gb/s using a multimode launch at 1310nm.

We demonstrate the transmission of 25Gb/s multimode optical signals over a record length of 300m multimode fiber designed for high modal bandwidth at 1310nm. The power penalty is 1.8 dB at 10(-12) bit error rate level.

Transmission of 112 Gb/s PM-QPSK signals over up to 635 km of multimode optical fiber.

We investigate transmission of 112 Gb/s PM-QPSK signals over 50 µm core diameter OM3 multimode fiber using the center launch approach. We demonstrate successful transmission of 16 DWDM channels over a distance of 635 km for a capacity-distance product of 1016 Tb/s-km. The limiting impairment appears due to mode coupling and multipath interference effects.

Pulse shaping for 112 Gbit/s polarization multiplexed 16-QAM signals using a 21 GSa/s DAC.

The implications of increasing the symbol rate for a given digital-to-analog converter (DAC) sampling rate are investigated by considering the generation of 112 Gbit/s PM 16-QAM signals (14 Gsym/s) using a 21 GSa/s DAC with 6-bit resolution.