An optical access network includes a first ring and a second ring communicating optical signals in opposite directions. The adhesion of the novel pressure-sensitive adhesive tape in its production process is controlled so as to be moderately weak. The body assembly has a circular cross-sectional exterior shape at a first end portion thereof. The real-time data analysis system 160 may send an emergency alert about the emergency event. The external frequency-selective reflector may comprise a waveguiding element such as a single-mode fiber incorporating a Bragg grating, and may also comprise a Fabry-Perot etalon. In this configuration, the light output from the laser diode is directly proportional to the input voltage to the operational amplifier and is independent of the laser diode’s temperature characteristics.