High-Bandwidth Graded-Index Plastic Optical Fiber With Low-Attenuation, High-Bending Ability, and High-Thermal Stability for Home-Networks

The graded-index plastic optical fiber (GI-POF) is expected to be a communication medium for the next-generation optical home network because of its simple-to-use connection, installation, and high bandwidth. In spite of the expectation, we had a problem that a typical GI-POF using poly (methyl methacrylate) (PMMA) had high transmission loss in the expected communication wavelength band (VCSEL: 670-680 nm) for home networks; the required values of being below 200 dB/km could not be achieved. We, therefore, propose poly (2, 2, 2-trichloroethyl methacrylate) (PTCEMA) as a base material for the GI-POF. A PTCEMA-based GI-POF was fabricated, and its characteristics were evaluated. The PTCEMA is a prominent material in terms of its transparency and heat-resistant property. Our results demonstrated that the fabricated fiber surpassed the desired characteristics for the home network pertaining to attenuation and heat resistance. Specifically, the attenuation in the wavelength band (670-680 nm) was 104-136 dB/km, and the glass transition temperature (T_g) was 102°C in the core center where the T_g was at its lowest. Moreover, we confirmed that our PTCEMA-based GI-POF had sufficient mechanical strength and low bending loss. These results indicate that our novel GI-POF can be a candidate for home networks.

I. Introduction

Today, a number of services, which include large information contents like high-definition movies, is rapidly growing. Single-mode glass optical fiber (SMF) has been utilized in trunk lines, becoming the indispensable information transmission medium in the form of large information pipelines connecting large cities and nations. However, the core diameter of the SMF is very small (10 m), and an extremely precise technique is required for connecting the fibers to signal-receiving devices. For this reason, it would be difficult to install the SMF for optical home networks.