This module specifies the Attributes of the optical paths used in the VL imaging. Each optical path is a combination of illumination, filters, lenses, and sensors, and each combination is identified for possible reference by Attributes in other Modules. This assembly comprises a light source, such as a laser diode or a semiconductor light-emitting diode (LED), an optical interface, a. An optical module is a typically hot-pluggable optical transceiver used in high-bandwidth data communications applications. OSAs generally fall into three main categories: TOSA, ROSA, and BOSA. • TOSA TOSA: Transmitting Optical Sub-Assembly.