Low-cost cooler-less signal sources for C-WDM applications

Abstract

We report the performance of coarse-WDM (C-WDM) uncooled DFB lasers for upper 8 C-WDM wavelengths (1470∼1610nm). Due to well-designed structures and well-controlled detuning, low threshold current, high slope efficiency, and high side-mode suppression ratio were maintained even at 85°C. For 2.5Gbps digital applications, these uncooled DFB lasers have clear eye opening, and can transmit through 100km standard single mode fiber with small dispersion penalty (<ldB). For repeater application of mobile communication system, low Relative Intensity Noise (RIN) level of -165dB/Hz at 2.2GHz and -168dB/Hz at 800MHz were achieved respectively at an optimized bias current of over 55mA, and third order distortion (IMD3) was less than -60dBc even at 85°C. For CATV return-path applications, second order distortion (IMD2) of less than -50dBc and IMD3 of less than -65dBc were achieved at 85°C. We performed accelerated aging test and estimated median lifetime was 10 5 hours at 85°C with output power of 5mW.