We proposed a hybrid wavelength-space division multiplexing (WSDM) optical ac- cess network architecture utilizing multicore fibers (MCFs) with advanced modulation formats. As a proof of concept, we experimentally demonstrated a WSDM optical access network with du- plex transmission using our developed and fabricated multicore (7-core) fibers and fan-in/fan-out device with 58.7 km distance. With QPSK-OFDM modulation format, the aggregation down- stream (DS) capacity reaches 250 Gb/s using 5 outer cores and it can be further scaled to 1 Tb/s using 16 QAM-OFDM. For upstream (US) transmission, wavelengths seeded from DS using the inner core are modulated with DMT signal adapted with the channel conditions and then trans- mitted back to the OLT through the 6th outer core. As an emulation of high speed mobile backhaul (MB) transmission, IQ modulated PDM-QPSK signal with 48 Gb/s per wavelength is transmitted in the inner core of MCF and coherently detected in the OLT side. Both DS and US optical signal exhibit acceptable performance with sufficient power budget. Recently, the bandwidth demand for the access network has witnessed a sharp increase driven by various services like business IP traffic, super HD video, mobile traffic backhaul and social networking, etc. [1]. Multiple candidates have been proposed to satisfy the requirements, such as passive optical networks based on WDM [2], TWDM [3], and OFDM [4]. However, the access capacity, transmission distance and subscriber number are still limited just using conventional technical methods. The space division multiplexing (SDM) technique based on few mode fibers (FMF) or multi-core fibers (MCF) has been proposed to be a favorable solution to accomplish the fiber capacity crunch in both long-haul transmission [5] and short-reach access network [6, 7]. Although the FMF based access network example has been reported very lately [6], the differential modal dispersion and modal interference may hinder its deployment in the access network region and MCF is actually a better choice owing to its well-controlled inter-core crosstalk and almost identical transmission quality compared with standard single mode fibers (SSMF). Zhu et al. demonstrated a 7-core based optical access network using traditional TDM-PON technologies [7]. However, the access data rate and the fiber link distance are quite limited (2.5 Gb/s and 11.3 km). Moreover, as a universal platform for wired/wireless data services, the optical access network plays even more important role in the 4G/5G mobile data transmission [8] and it is also interesting to envision the application of MCF in the fiber/wireless converged networks. In this paper, we proposed a hybrid wavelength-space division multiplexing (WSDM) optical access network architecture utilizing multicore fibers with advanced modulation formats, as shown in Figure 1. In our proposed architecture, the most prominent feature is that a physically isolated fiber channel (the inner core of a typical 7-core MCF for example) is allocated to the wireless data transmission such as the mobile backhaul transmission considering the mobile internet demand is booming. One of the outer cores of MCF is utilized to transmit US signal while the others are employed as the parallel channels for DS transmission, thus the Rayleigh backscattering noise can be eliminated even though the same wavelengths are reused for both DS and US. In the OLT block, m wavelengths are utilized as the laser source. For each wavelength in one subset OLT, it is power split by N − 1 in which N representing the number of cores of MCF. 1/(N − 1) of the signal power is left as the optical carrier for US signal modulation which is delivered to the ONU side via the inner core. In this way, this configuration can support (N − 1) × m subscribers only employing m wavelengths that can lower the expense compared with the same situation in WDM-PON. To further enhance the capacity with affordable cost and complexity, downstream Progress In Electromagnetics Research Symposium Proceedings 2169