Injection-locked optical orthogonal frequency-division multiplexing for radio-over-fiber communications

A novel injection-locked optical orthogonal frequency-division multiplexing (ILO-OFDM) method using an optically injection-locked semiconductor laser is presented in this paper. In this system, an optically injected semiconductor laser under stable locking takes the role of an optical modulator to directly impose the OFDM signal on the optical carrier intensity. The goal is to achieve the maximum enhanced modulation bandwidth with desirable flatness while simultaneously reducing signal distortions due to the effects of nonlinearities, frequency chip, and noise. This method is effective for broadband radio-over-fiber communications systems.