Laser diode module multi-layer board and laser diode module

Abstract

A light emitting/receiving unit including a laser diode (LD) and a light receiving element, and an LD protection component for protecting the LD from electric damages are mounted on a multi-layer board for integration into a single module. A circuit for superposing a high-frequency current on an LD driving signal, and an anti-EMC circuit for reducing electromagnetic noise produced from this circuit may be included in the module, where at least some of elements making up these circuits may be incorporated into the board. In this structure, in order to reduce the distance between a coil and a capacitor included in the anti-EMC circuit, the capacitor is arranged within the board at a position substantially beneath the coil mounted on a surface of the board.

Dependencies are inferred from the claim text.