Advanced semiconductor light sources
Efficient photonic sources are a key element for reliable digital transmission. Photonic devices such as compact and cost-effective pulse lasers with low timing jitter – timing errors – are an indispensable tool in ADC conversion. The EU-funded project VELO MOLO_780 (Very low jitter mode locked laser at 780nm for optical sampling applications) is investigating suitable pulse lasers emitting at 780 nm with ultrashort laser pulses for use as high-speed sampling signals in photoconductive switches. Ultrashort optical pulses hitting a photoconductive switch enable very fast ADC converter operation. Scientists used the mode-locking method to obtain ultrashort laser pulses through monolithic or external-cavity lasers. Several laser architectures based on semiconductor optical amplifiers were studied involving use of either indium phosphide or gallium arsenide layer structures. VELO MOLO_780's ultimate aim is the design, fabrication and testing of an improved pulse laser design, and semiconductor lasers are promising candidates for cheap and compact-size lasers.
Keywords
Light sources, semiconductor lasers, optical sampling, analogue-to-digital, ultrashort laser pulses