Spectral linewidth narrowing in monolithic grating-surface-emitting laser arrays

Linewidth measurements of single-element grating-surface-emitting (GSE) lasers and coherent three-element GSE arrays have shown that a significant reduction in the spectral linewidth is possible in the case of the coherent array. A monolithic array of three injection-coupled GSE lasers had a linewidth less than 300 kHz, whereas a single-array element, operated by itself, typically had a linewidth of about 6 MHz.<
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