A Londonderry [juin 1920, soldat britannique couché à terre] en attente : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 59873

Londonderry, une ronde [de soldats britanniques] dans les rues désertes : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 59872

[Le] destroyer [HMS Wivern D66] dans le port de Londonderry : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 59877

Londonderry [vue générale depuis le port] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 59878

Uncooled DBR laser directly modulated at 3.125 Gb/s as athermal transmitter for low-cost WDM systems

An uncooled three-section tunable distributed Bragg reflector laser is demonstrated as an athermal transmitter for low-cost uncooled wavelength-division-multiplexing (WDM) systems with tight channel spacing. A ±0.02-nm thermal wavelength drift is achieved under continuous-wave operation up to 70 °C. Dynamic sidemode suppression ratio of greater than 35 dB is consistently obtained under 3.125-Gb/s direct modulation over a 20 °C-70 °C temperature range, with wavelength variation of as low as ±0.2 nm. This indicates that more than an order of magnitude reduction in coarse WDM channel spacing is possible using this source. © 2005 IEEE.