LASER diode-based transmitter module for optical wireless communications

Abstract

In this paper, we present the design of an analog transmitter based on a blue LD targeting optical wireless communications, suitable for OFDM signals. The approach relies on a thorough characterization of the individual components of the module, whence a detailed circuit model is obtained to design an impedance matching circuit for improved performance, prior to fabrication. The impedance matching is based on non-uniform transmission lines and works well over a wide frequency range (100 MHz to 2 GHz). The results are experimentally validated by the transmitter response exhibiting an increased 6 dB bandwidth limit and 1 GHz bandwidth improvement.

5.36 Gbit/s OFDM optical wireless communication link over the underwater channel

“…At the output of the bias-tee, both RF signal and bias are combined which directly modulates the LD. Prior to the modulation, an additional circuit is used to match the impedance of the LD [6].…”