We propose a double contact Fabry-Perot laser diode (F-P LD) as a temperature-independent wavelength-division-multiplexing source. By controlling injection currents of the double contact F-P LD, we achieve a fixed lasing envelope regardless of temperature variation. We also demonstrate error-free transmission using the double contact F-P LD as a wavelength-locking source within a 20 degrees C operating temperature range.