Two-Channel OTDM System for Data-Center Interconnects: A Review.

It has been proposed to implement the >100 Gb/s data-center interconnects using a two-channel optical time-division multiplexed system with multilevel pulse-amplitude modulation. Unlike the conventional four-channel optical time-division multiplexed system which requires an expensive narrow pulse, the two-channel system can be implemented cost-effectively using a wide pulse (which can be simply generated using a single modulator). The two-channel system is expected to be practically available using an integrated transmitter in a chip due to the recent advances in photonics-integrated circuits. This paper reviews the current stage of research on a two-channel optical time-division multiplexed system and discusses possible research directions. Furthermore, it has been demonstrated that 200 Gb/s signals can be generated by using modulators with only 17.2 GHz bandwidth. Therefore, the use of the phase-alternating pulse can make the multiplexed signal robust to chromatic dispersion, enabling the 200 Gb/s 4-level pulse-amplitude-modulated signal to be transmitted over 1.9 km of standard single-mode fiber.

Self Capacitance Mismatch Calibration Technique for Fully-Differential Touch Screen Panel Self Capacitance Sensing System.

This paper presents a fully-differential touch screen panel (TSP) self-capacitance sensing (SCS) system with a self-capacitance mismatch calibration technique. Due to the self-capacitance mismatch of TSP, the analog front-end (AFE) of the receiver (RX) circuit suffers from dynamic range degradation and gain limitations, which lead to the signal-to-noise ratio (SNR) loss for the TSP SCS system. The proposed calibration introduces the difference in input resistance and the driving amplifier's strength between the fully-differential input. Thus, the mismatch effect is efficiently relieved in terms of area and power consumption. The proposed calibration restores the SNR by 19.54 dB even under the worst self-capacitance mismatch case.

Simple SSMF-based two-channel MGDM system operating in the 0.8 µm wavelength region.

We propose a simple two-channel mode-group-division-multiplexing (MGDM) system operating in the 0.8 µm region over the standard single-mode fiber (SSMF). For the cost-effectiveness, we implement its receiver by using only two photodetectors (PDs) [instead of three PDs required for the detection of the LP01,LP11a, and LP11b modes]. We then detect the signal carried by the LP01 mode by using a PD and a mode filter. On the other hand, the other signal carried by the LP11 mode group is detected by using another PD and a multiple-input single-output equalizer (i.e., by subtracting the signal carried by the LP01 mode from the multiplexed signal). For a demonstration, we transmit 2×28Gb/s MGDM on-off keying signal operating at 852.6 nm over 2.2 km of the SSMF by using the proposed technique. The results show that we can achieve the bit-error rate of <3.8×10-3 for both the LP01 and LP11 modes.