Optical clock generation and carrier extraction techniques using 790 nm self-pulsating laser diodes

Self-pulsating laser diodes (SP-LD) emitting at 790 nm wavelength have found widespread application as low-noise, low-cost optical sources in compact disc (CD) systems. The requisite immunity to reflection-induced noise is obtained by gigahertz frequency self-pulsation of the laser emission coupled with significant chirping of each Fabry-Perot mode. It is the resultant low-coherence of the optical output which reduces CD reflection noise. Subsequent work has shown that the SP-LD characteristics as described by Poh (1985) predict a pronounced modulation transfer function nonlinearity at the self-pulsation frequency and also well-defined injection-locking behaviour. These effects are exploited in the experimental work described