A passive optical network (PON) is a highly capable access network that effectively converges several service providers, without suffering from any bandwidth deficiency. However, a PON consisting of a single optical line terminal (OLT) for multiple service providers increases the computational complexity for data packet processing in the OLT, resulting in a… (More)
An integrated fiber-to-the-homes (FTTHs) and wireless sensor network (WSN) provides a cost-effective solution to build up an immaculate ubiquitous-City (U-city). The key objectives of effective convergence of FTTH and WSN are less computational complexity for data packet processing, low installation cost, and good quality of services. In this paper, we… (More)
The use of the downhill simplex method is proposed for multivariate identification of phase difference and reflectivity of low-loss sampled fiber Bragg gratings (SFBGs). Phase differences between two FBGs, which are determined by optical lengths between two adjacent FBGs, are the most important parameter in SFBG fabrication. The frequency of phase… (More)
Effect of I/Q imbalance on multi-level modulated signals interleaved with reference light is analytically investigated. We show that received signals are degraded by the I/Q imbalance resulting from optical-frequency misalignment between a light source and an optical delay interferometer. Then, quality of the received signals is evaluated by numerical… (More)
We propose and experimentally demonstrate upstream transmission in a wavelength division multiplexing/optical code division multiplexing (WDM/OCDM) passive optical network (PON) without using any high-cost devices such as mode-locked lasers or LiNbO<sub>3</sub> external modulators. To make optical network units (ONUs) simple, a loop-back transmission of… (More)
Concatenated optical coding provides channel grouping ability on OCDM networks. With the 16-chip optical code concatenating two 4-chip Fourier codes, selection of a channel in sixteen or a code group in four is experimentally demonstrated.