Abstract
Persistent efforts on developing advanced and complex data algorithms to enable the vertical-cavity surface-emitting lasers (VCSELs) for data beyond 100-Gbit/s has been reviewed in this paper. This endeavor not only elevates the bit rate of the IEEE802.3 standards for data center applications but also to initiate the unification of data format for wired and wireless network coverage. To date, the highest allowable data rates of the single-VCSEL-based optical link are 80 Gbit/s for the NRZ-OOK format under back-to-back (BtB) transmission 168 Gbit/s for the PAM-4 format over 150-m OM5 MMF, and the 224 Gbit/s for the QAM-OFDM format at BtB case. For the high-level complex data-format transmission with rigorous demand on the signal-to-noise ratio (SNR), this work demonstrates the most up-to-date 32-ray quadrature amplitude modulation generalized frequency division multiplexing (32-QAM GFDM) data algorithm with optimized amplitude and K value for encoding the multimode (MM) VCSEL. To achieve the higher spectral-usage efficiency based on the SNR spectrum for maximal transmission data rate, the bit-loading discrete multi-tone (DMT) technique is implemented by rearranging each subcarrier to the appropriate QAM levels. By utilizing 32-QAM GFDM and bit-loading DMT, the maximal data rate in the BtB case could respectively achieve 119.5 Gbit/s and 130 Gbit/s when operating the MM VCSEL at 55 °C. The transmission capacity of the VCSEL operated at 55 °C would decrease to 93.8 Gbit/s for 32-QAM GFDM and 83 Gbit/s for bit-loading DMT after propagating through OM5 MMF with modal dispersion.
Highlights
The developing progress on the structural design and data algorithms to enable the vertical-cavity surface-emitting lasers (VCSELs) for transmitting multiple complex data formats beyond 100-Gbit/s has been reviewed in this paper
The developing progress on the structural design and data algorithms to enable the VCSELs for transmitting multiple complex data formats beyond 100-Gbit/s has been reviewed in this paper
By modulating the MM VCSEL operated at a DC bias of 17 mA with a peak-to-peak amplitude of the GFDM data at 800 mV, the error vector magnitude (EVM), signal-to-noise ratio (SNR), and BER of the receiving 32-QAM GFDM data can be respectively improved to 10%, 20 dB, and 6.15 10-4 by setting the K number of 2
Summary
During the past two decades, various researches about the VCSELs carrying the simplest non-return-to-zero on-off keying (NRZ-OOK) data format were reported to initiate the short-reached data-center applications from many academic research groups. In 2012, Westbergh and co-workers demonstrated the NRZ-OOK transmission at 47 Gbit/s in BtB case and at 44 Gbit/s over 50-m OM4 MMF link carried by the 7- m-oxide-confined VCSEL with a modulation bandwidth of 28 GHz [15]. Lott et al enhanced the modulation efficiency and impedance matching of the VCSEL via the diameter variation of the oxide-confined aperture to respectively deliver the NRZ-OOK data at 55 Gbit/s and 43 Gbit/s in BtB and 100-m OM4 MMF cases [19]. In 2016, Chi et al obtained the quasi-SM VCSEL with an analog bandwidth of 27 GHz via the Zn-diffusion technology and oxide-relief aperture to transmit the NRZ-OOK data at 54 Gbit/s with a bit-error-rate (BER) of 1.4×10-4 over 1-km OM4 MMF [25]. 2011 [13] 2011 [14] 2012 [15] 2012 [16] 2014 [17] 2014 [18] 2013 [19] 2013 [20] 2014 [21]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
