Low-cost and miniaturized 100-Gb/s (2 × 50 Gb/s) PAM-4 TO-packaged ROSA for data center networks.

We design and implement a cost-effective and compact 100-Gb/s (2 × 50 Gb/s) PAM-4 receiver optical sub-assembly (ROSA) by using a TO-can package instead of an expensive box-type package. It consists of an optical demultiplexer, two PIN-PDs and a 2-channel linear transimpedance amplifier. The components are passively aligned and assembled using alignment marks engraved on each part.

Highly alignment tolerant and high-sensitivity 100Gb/s (4 × 25Gb/s) APD-ROSA with a thin-film filter-based de-multiplexer.

We investigate and demonstrate a 100-Gb/s (4x25-Gb/s) receiver optical sub-assembly (ROSA) based on avalanche photodiodes and a thin-film filter-based de-multiplexer. The overall alignment tolerances of the ROSA are relaxed to have larger than ± 25 μm by improving optical coupling structure. The receiver sensitivity of each lane is also measured to be less than -22.

Real-time demonstration of QoS guaranteed 25-Gb/s PON prototype with Ethernet-PON MAC/PHY and cost-effective APD receivers for 100-Gb/s access networks.

We demonstrate a real-time 25-Gb/s PON prototype with ethernet-PON MAC/PHY, O-band transmitter, and cost-effective APD receivers. With applying parasitic inductance and capacitance reduction, the frequency response of 25-Gb/s APD ROSA with TO46-pacakge is improved to support high receiver sensitivity around -25 dBm at the BER of 10. The 30 dB power budget of 25 Gb/s downstream is achieved at the BER of 10.

Experimental demonstration of wavelength domain rogue-free ONU based on wavelength-pairing for TDM/WDM optical access networks.

In this study, we propose and experimentally demonstrate a wavelength domain rogue-free ONU based on wavelength-pairing of downstream and upstream signals for time/wavelength division-multiplexed optical access networks. The wavelength-pairing tunable filter is aligned to the upstream wavelength channel by aligning it to one of the downstream wavelength channels. Wavelength-pairing is implemented with a compact and cyclic Si-AWG integrated with a Ge-PD.

Self-wavelength initialization method for the Bragg-grating based tunable light source in WDM passive optical network.

We propose a self-wavelength initialization method for the waveguide Bragg-grating based tunable external cavity laser. Reflection characteristics of the Bragg-grating, and the wavelength routing property in the wavelength division multiplexing-passive optical network (WDM-PON) were used in our proposed method. By adding a cost-effective and low- power broadband light source in the central office, the tunable laser can align its output wavelength with the wavelength at the center of the pass band of the WDM multiplexer.

Demonstration of burst mode bit discrimination circuit for 1.25 Gb/s and 10.3 Gb/s dual-rate reach extender of WDM-TDM-hybrid-PON systems based on 10G-EPON.

We proposed a simple and cost-effective burst mode bit discrimination circuit for dual rate reach extender based on 10 gigabit Ethernet passive optical network. To distinguish the dual rate burst mode packets, periodic idle patterns which have specific frequency components in the frequency domain and radio frequency power detection technique were used. The burst mode dual rate upstream transmission was demonstrated to confirm the feasibility of our suggested method in a coexisted gigabit Ethernet passive optical network and 10 gigabit Ethernet passive optical network.