DFB laser reallocation by thermal wavelength control for statistical udWDM in PONs

Abstract

We demonstrate a simple fast method of laser wavelength channel switching for the wavelength management of UDWDM-PONs where the ONUs have source wavelengths with random distribution and are controlled with limited thermal tunability.Peer ReviewedPostprint (published version

DQPSK Directly Phase Modulated DFB for Flexible Coherent UDWDM-PONs

“…The electrical signal modulating the DFB needed high power to produce the required phase shifts. This produced instantaneous changes in the temperature of the laser which caused wavelength drifts [13]. Since there was no frequency offset estimation these drifts produced around 1dB penalty [14].…”

Automatic <inline-formula> <tex-math notation="LaTeX">$\lambda $ </tex-math></inline-formula>-Control With Offset Compensation in DFB Intradyne Receiver for udWDM-PON

“…Next, a 400kHz I 2 C digital interface via USB port drives the D/A conversion towards the LO control. The thermally tunable DFB laser used as LO implements an electronic fast frequency tuning system by simultaneous control on the bias current and the thermoelectric cooler available in the DFB package, with a time constant of 700ns for frequency shifts [11].…”

Technologies for Cost-Effective udWDM-PONs

“…The overall cost of the access network, dominated by the user equipment, can thus be minimized. This novel concept implies a radical new management procedure of the optical spectrum and terminals, as well as for the activation of additional ONUs in the spectrum in a hitless form [19,[22][23][24].…”

“…The minimum wavelength separation between two adjacent channels can be as low as 3 GHz [24], but it was found convenient to leave few GHz as guard band. In this study, the laser tunability is here assumed to be 0.1 nm/ºC as typical in DFBs, with a tuning range of 2 nm (250 GHz) by +/-10ºC, that can be easily achieved with a Peltier cell, or just by > REPLACE THIS LINE WITH YOUR PAPER IDENTIFICATION NUMBER (DOUBLE-CLICK HERE TO EDIT) < 3 heating.…”