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Optical interconnects have been highlighted as a key technology to alleviate the shortcomings inherent to traditional inter-chip copper interconnects in terms of bandwidth, power consumption and reliability [1]. In particular, the monolithic two-section quantum dot passively mode-locked laser (QDMLL) has emerged as an impressive low noise source of pico-second optical pulses [2]. As well as its compact size and direct electrical pumping, the QDMLL emits at wavelengths compatible with Si-based waveguides and detectors. For use in optical interconnects, ideally, the transmitter will be situated close to the CPU cores and will therefore need to operate over a broad temperature range, with highs typically in the vicinity of 100 °C. It is therefore desirable to develop uncooled optical interconnects, firstly to reduce system size and complexity and secondly to eliminate the power-hungry cooling requirements associated with diode lasers. In this paper, we discuss our approach to developing uncooled, ultra low energy/bit QD MLL transmitters capable of providing high quality optical pulse trains suitable for multiplexing up to the 100s of Gbps level. Up until now an analytical method to guide the design of temperature resistant MLLs based on convenient, measureable material parameters has not existed.