Continuous Wave Light Injection Research Articles

Experimental demonstration of CW light injection effect in upstream traffic TDM-PON

High capacity time-division-multiplexed passive optical network (TDM-PON) is an emerging fiber access network that deploys optical access lines between a carrier’s central office (CO) and a customer sites. In this investigation, we demonstrate and analyze the continuous wave (CW) upstream effect in TDM-PONs. Besides, we also propose and design a protection apparatus in each optical network unit (ONU) to avoid a CW upstream traffic in TDM-PONs due to sudden external environment change or ONU failure. When an upstream CW injection occurs in TDM access network, the protection scheme can stop the CW effect within a few ms to maintain the entire data traffic.

Chirp control and broadband wavelength-tuning of 40-GHz monolithic actively mode-locked laser diode module with an external CW light injection

Chirp control behaviors of a 40-GHz monolithic actively mode-locked laser diode (MLLD) with an external continuous wave (CW) light injection were experimentally investigated in detail. Large frequency chirping of the Fabry-Pe/spl acute/rot-type MLLD was found to be reduced by the CW light input with sufficient power. Broad-band wavelength tuning over 60 nm was also successfully achieved using the external CW light as a wavelength-selection element. Optical short pulses shorter than 4 ps were generated leaving small frequency chirping, low timing jitters less of than 0.2 ps, and low relative intensity noise values of less than -130 dB/Hz over the whole tuning range from 1530 to 1592 nm, almost covering both the C and the L bands in the wavelength region of optical communication systems.